Test and polish encoding extra directories

There are two kinds of directories: those that are image directories
directly in the TIFF file's main sequence, and directories that follow
the structure but represent auxiliary data. The method will link the
directory into the main sequence but those images have additional
requirement on their IFDs which is not clear to the caller. We make that
explicit and also provide a way to write auxiliary directories.

.github/workflows/rust.yml

@@ -0,0 +1,90 @@
+name: Rust CI
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust: ["1.74.0", stable, beta, nightly]
+    steps:
+    - uses: actions/checkout@v2
+
+    - uses: dtolnay/rust-toolchain@nightly
+      if: ${{ matrix.rust == '1.74.0' }}
+    - name: Generate Cargo.lock with minimal-version dependencies
+      if: ${{ matrix.rust == '1.74.0' }}
+      run: cargo -Zminimal-versions generate-lockfile
+
+    - uses: dtolnay/rust-toolchain@v1
+      with:
+        toolchain: ${{ matrix.rust }}
+    - name: Cache Cargo Dependencies
+      uses: Swatinem/rust-cache@v2
+      with:
+        cache-on-failure: true
+    - name: build
+      run: cargo build -v
+    - name: test
+      if: ${{ matrix.rust != '1.74.0' }}
+      run: cargo test -v && cargo doc -v
+
+  features:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        feature: ["", deflate, jpeg, lzw, zstd, default, "default,zstd"]
+    steps:
+    - uses: actions/checkout@v2
+    - uses: dtolnay/rust-toolchain@stable
+      with:
+        components: clippy
+    - name: Cargo check
+      run: cargo check --features "${{ matrix.feature }}" --no-default-features
+
+  other_archs:
+    # github actions does not support 32-bit or big endian systems directly, but
+    # it does support QEMU. so we install qemu, then build and run the tests on
+    # emulated systems. NOTE: you can also use this approach to test locally.
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        arch: [powerpc-unknown-linux-gnu, i686-unknown-linux-gnu]
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install or use cached cross-rs/cross
+        uses: baptiste0928/cargo-install@v2
+        with:
+          crate: cross
+      - name: Cache Cargo Dependencies
+        uses: Swatinem/rust-cache@v2
+        with:
+          cache-on-failure: true
+          key: ${{ matrix.arch }}
+      - name: Start Docker (required for cross-rs)
+        run: sudo systemctl start docker
+      - name: Cross-Run Tests using QEMU
+        run: cross test --target ${{ matrix.arch }}
+
+  rustfmt:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: dtolnay/rust-toolchain@stable
+      with:
+        components: rustfmt
+    - name: Run rustfmt check
+      run: cargo fmt -- --check
+
+  clippy:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: dtolnay/rust-toolchain@stable
+      with:
+        components: clippy
+    - run: cargo clippy --all-features # TODO: enable "-- -D warnings" once all outstanding clippy lints are fixed

.travis.yml

@@ -1,6 +0,0 @@
-language: rust
-rust:
-    - 1.34.2
-    - stable
-    - beta
-    - nightly

CHANGES.md

@@ -1,3 +1,218 @@
+# Version 0.10.0
+
+New features:
+- Added `ColorType::Multiband` and `ColorType::CMYKA`.
+- Added `Value::Byte` and `Value::SignedByte` to represent `u8` and `i8` tags.
+- Encoding can now use horizontal predictor.
+- The `Decoder::tag_iter` method allows iterating over all tags in the image.
+- Half precision floating point values are now supported during decoding.
+- ZStandard compression has been added as an additional compression method
+  during decoding, but requires the `zstd` feature flag.
+
+Changes:
+- Switched `u16` and `i16` values to be intepreted as `Value::Short` and
+  `Value::SignedShort` respectively.
+- Changed JPEG compression to use the `zune-jpeg` crate instead of
+  `jpeg-decoder`.
+- The `deflate`, `jpeg`, and `lzw` compression methods are now controlled by
+  (enabled by default) feature flags.
+
+Fixes:
+- Fixed a bug in 1 bit-per-pixel decoding.
+
+# Version 0.9.1
+
+New features:
+- Basic support for planar configuration.
+- Allow arbitrary number of samples as long as all have the same bit depth.
+
+Fixes:
+- Don't panic when parsing metadata when custom compression is used.
+
+# Version 0.9.0
+
+New features:
+* Added support for photometric interpretation `YCbCr` and added related
+  `ColorType`.
+
+Fixes:
+* Decoding tiled images calculates padding correctly when image width or height
+  is a multiple of tile size. It could previously corrupt the last tile per row
+  by skipping over data.
+
+# Version 0.8.1
+
+Changes:
+* The jpeg decoder gained to ability to utilize the Photometric Interpretation
+  directly instead of relying on a custom APP segment.
+
+Fixes:
+* A spurious error within the PackBits decoder lead to the incorrect results
+  (wrong bits or errors), based on the maximum size of reads from the
+  underlying reader.
+* Removed a panic path in jpeg decoding, when a feature such as photometric
+  interpretation is not supported. An error is returned instead.
+
+# Version 0.8.0
+
+Changes:
+* The minimum supported rust version is now indicated in `Cargo.toml`.
+* The enums `TiffFormatError` and `TiffUnsupportedError` are now
+  marked with the `#[non_exhaustive]` attribute. 
+* Additionally, tag related enums `Value`, `Tags`, `Type`, `CompressionMethod`,
+  `PhotometricInterpretation`, `PlanarConfiguration`, `Predictor`,
+  `ResolutionUnit`, `SampleFormat` are also changed.
+
+Removals:
+* Removed deprecated methods of `Decoder`: `init`, `read_jpeg`,
+  `read_strip_to_buffer`, `read_strip`, `read_tile`. The implicit chunk (row or
+  tile) index order could not be easily tracked by the caller. New separate
+  utility interfaces may be introduced at a later point, for now callers are
+  obligated to choose their own.
+
+Fixes:
+* Update to `jpeg_decoder = 0.3`.
+
+# Version 0.7.4
+
+New features:
+* Creating an encoder for invalid, zero-sized images is now rejected.
+
+Fixes:
+* Fix panic, in a case where decoding jpeg encoded images did not expect the
+  jpeg decoder to return an error.
+* Fix panic by validating `rows_per_strip` better, fixing a division-by-zero.
+
+# Version 0.7.3
+
+New features:
+* Allow decoder to access specific tiles by index.
+* Add support for floating point predictor.
+* Tiled jpeg file support.
+
+Changes:
+* Various refactoring and performance improvements.
+
+# Version 0.7.2
+
+New features:
+* Encoding with `ImageEncoder` now takes an optional compressor argument,
+  allowing compressed encoding. See the methods 
+  `TiffEncoder::{new_image,write_image}_with_compression`.
+* `jpeg_decoder` has been upgraded, now supports lossless JPEG.
+
+Changes:
+* Decoding now more consistently reads and interprets the initial IFD, instead
+  of performing _some_ interpretation lazily. (This change prepares fully lazy
+  and backwards seeking.)
+
+# Version 0.7.1
+
+New features:
+* Encoding signed integer formats is now supported.
+* Extensive fuzzing with `cargo fuzz`.
+
+Changes:
+* Tile decoding should be a little faster, requires one less intermediate buffer.
+* Images whose IFDs form a cycle due to their offsets will now raise an error
+  when the cycle would be entered (jumping back should still be supported).
+
+Fixes:
+* Fixed a regression that caused conflict between strips and tile images,
+  causing errors in decoding some images.
+* Use checked integer arithmetic in limit calculations, fixes overflows.
+* IFD Tags are now always cleared between images.
+* Found by fuzzing: Several memory limit overflows; JPEG now correctly
+  validates offsets and a minimum size of its table; Check upper limit of strip
+  byte size correctly;
+
+Notes:
+Our CI has warned that this version no longer builds on `1.34.2` out of the
+box. We're still committed to the MSRV on this major version yet one
+dependency—`flate2`—has already bumped it in a SemVer compatible version of its
+own. This is out-of-our-control (cargo's dependency resolution does not allow
+us to address this in a reasonable manner).
+
+This can be address this by pinning the version of `flate2` to `1.0.21` in your
+own files. However, you should understand that this puts you in considerable
+maintenance debt as you will no longer receive any updates for this dependency
+and any package that _requires_ a new version of the `1.0` series would be
+incompatible with this requirement (cargo might yell at you very loudly).
+
+# Version 0.7.0
+
+New features:
+* Support for encoding BigTiff ([#122](https://github.com/image-rs/image-tiff/pull/122))
+  * _Breaking:_ Encoder types now have a generic parameter to differentiate BigTiff and standard Tiff encoding. Defaults to standard Tiff.
+* Basic tile decoding ([#125](https://github.com/image-rs/image-tiff/pull/125))
+  * _Breaking:_ There is a new `TiffError::UsageError` variant.
+* Support for datatypes `Int8` and `Int16` ([#114](https://github.com/image-rs/image-tiff/pull/114))
+  * _Breaking:_ `DecodingResult` and `DecodingBuffer` have the two new variants `I8` and `I16`.
+* Support for `i32` arrays ([#118](https://github.com/image-rs/image-tiff/pull/118/files))
+  * _Breaking:_ `DecodingResult` and `DecodingBuffer` have a new `I32` variant.
+* Support for `Ifd` and `IfdBig` tag types and `I64` data type ([#119](https://github.com/image-rs/image-tiff/pull/119))
+  * _Breaking:_ `DecodingResult` and `DecodingBuffer` have a new `I64` variant.
+* Add `SMinSampleValue` and `SMaxSampleValue` ([#123](https://github.com/image-rs/image-tiff/pull/123))
+
+Changes:
+* Improve deflate support ([#132](https://github.com/image-rs/image-tiff/pull/132))
+  * Switch to streaming decompression via `flate2`. Aside from performance improvements and lower RAM consumption, this fixes a bug where `max_uncompressed_length` was precalculated for a single tile but then used as a hard limit on the whole data, failing to decompress any tiled images.
+  * Add support for new `Deflate` tag in addition to `OldDeflate`.
+* _Breaking:_ Remove `InflateError`, which is no longer needed with `flate2` ([#134](https://github.com/image-rs/image-tiff/pull/134))
+* _Breaking:_ Support for `MinIsWhite` is restricted to unsigned and floating
+  point values. This is expected to be be re-added once some contradictory
+  interpretation regarding semantics for signed values is resolved.
+
+Fixes:
+* Validate that ASCII tags are valid ASCII and end with a null byte ([#121](https://github.com/image-rs/image-tiff/pull/121))
+
+Internal:
+* Simplify decompression logic ([#126](https://github.com/image-rs/image-tiff/pull/126))
+* Simplify `expand_strip` ([#128](https://github.com/image-rs/image-tiff/pull/128))
+
+# Version 0.6.1
+
+New features:
+* Support for reading `u16` and ascii string tags.
+* Added `Limits::unlimited` for disabling all limits.
+* Added `ImageEncoder::rows_per_strip` to overwrite the default.
+
+Changes:
+* The default strip size for chunked encoding is now 1MB, up from 8KB. This
+  should lead to more efficient decoding and compression.
+
+Fixes:
+* Fixed a bug where LZW compressed strips could not be decoded, instead
+  returning an error `Inconsistent sizes encountered`.
+* Reading a tag with a complex type and a single value returns the proper Value
+  variant, instead of a vector with one entry.
+
+# Version 0.6.0
+
+New features:
+* Support for decoding BigTIFF with 64-bit offsets
+* The value types byte, `f32`, `f64` are now recognized
+* Support for Modern JPEG encoded images
+
+Improvements:
+* Better support for adding auxiliary tags before encoding image data
+* Switched to lzw decoder library `weezl` for performance
+* The `ColorType` trait now supports `SAMPLE_ENCODING` hints
+
+Fixes:
+* Fixed decoding of inline ASCII in tags
+* Fixed handling after null terminator in ASCII data
+* Recognize tile and sample format tags
+
+# Version 0.5.0
+
+* Added support for 32-bit and 64-bit decoded values.
+* Added CMYK(16|32|64) color type support.
+* Check many internal integer conversions to increase stability. This should
+  only lead to images being reported as faulty that would previously silently
+  break platform limits. If there are any false positives, please report them.
+* Remove an erroneous check of decoded length in lzw compressed images.
+
 # Version 0.4.0
 
 * Several enumerations are now non_exhaustive for future extensions.

Cargo.toml

@@ -1,25 +1,42 @@
 [package]
 name = "tiff"
-version = "0.4.0"
-authors = [
-    "ccgn",
-    "bvssvni <bvssvni@gmail.com>",
-    "nwin",
-    "TyOverby <ty@pre-alpha.com>",
-    "HeroicKatora",
-    "Calum",
-    "CensoredUsername <cens.username@gmail.com>",
-    "Robzz",
-    "birktj"]
+version = "0.10.0"
+edition = "2021"
+resolver = "2"
+
+# note: when changed, also update test runner in `.github/workflows/rust.yml`
+rust-version = "1.74.0"
+
 license = "MIT"
 description = "TIFF decoding and encoding library in pure Rust"
+authors = ["The image-rs Developers"]
+
 repository = "https://github.com/image-rs/image-tiff"
+categories = ["multimedia::images", "multimedia::encoding"]
+
 exclude = ["tests/images/*", "tests/fuzz_images/*"]
 
 [dependencies]
-byteorder = "1.2"
-lzw = "0.10"
-miniz_oxide = "0.3"
+half = { version = "2.4.1" }
+quick-error = "2.0.1"
+
+flate2 = { version = "1.0.20", optional = true }
+weezl = { version = "0.1.10", optional = true }
+zstd = { version = "0.13", optional = true }
+zune-jpeg = { version = "0.4.17", optional = true }
 
 [dev-dependencies]
-tempfile = "3.0"
+criterion = "0.3.1"
+
+[features]
+default = ["deflate", "jpeg", "lzw"]
+
+# Compression algorithms
+deflate = ["dep:flate2"]
+jpeg = ["dep:zune-jpeg"]
+lzw = ["dep:weezl"]
+zstd = ["dep:zstd"]
+
+[[bench]]
+name = "lzw"
+harness = false

README.md

@@ -1,6 +1,57 @@
 # image-tiff
-[![Build Status](https://travis-ci.org/image-rs/image-tiff.svg?branch=master)](https://travis-ci.org/image-rs/image-tiff)
+[![Build Status](https://github.com/image-rs/image-tiff/actions/workflows/rust.yml/badge.svg?branch=main)](https://github.com/image-rs/image-tiff/actions)
 [![Documentation](https://docs.rs/tiff/badge.svg)](https://docs.rs/tiff)
 [![Further crate info](https://img.shields.io/crates/v/tiff.svg)](https://crates.io/crates/tiff)
 
 TIFF decoding and encoding library in pure Rust
+
+## Supported
+
+### Features
+- Baseline spec (other than formats and tags listed below as not supported)
+- Multipage
+- BigTIFF
+- Incremental decoding
+
+### Formats
+This table lists photometric interpretations and sample formats which are supported for encoding and decoding. The entries are `ColorType` variants for which sample bit depths are supported. Only samples where all bit depths are equal are currently supported. For example, `RGB(8)` means that the bit depth [8, 8, 8] is supported and will be interpreted as an 8 bit per channel RGB color type.
+
+| `PhotometricInterpretation` | UINT Format                             | IEEEFP Format             |
+| --------------------------- | --------------------------------------- | ------------------------- |
+| `WhiteIsZero`               | Gray(8\|16\|32\|64)                     | Gray(32\|64)              |
+| `BlackIsZero`               | Gray(8\|16\|32\|64)                     | Gray(32\|64)              |
+| `RGB`                       | RGB(8\|16\|32\|64), RGBA(8\|16\|32\|64) | RGB(32\|64), RGBA(32\|64) |
+| `RGBPalette`                |                                         |                           |
+| `Mask`                      |                                         |                           |
+| `CMYK`                      | CMYK(8\|16\|32\|64)                     | CMYK(32\|64)              |
+| `CMYKA`                     | CMYKA(8)                                |                           |
+| `YCbCr`                     |                                         |                           |
+| `CIELab`                    |                                         |                           |
+
+### Compressions
+
+|          | Decoding | Encoding |
+| -------- | -------- | -------- |
+| None     | ✓        | ✓        |
+| LZW      | ✓        | ✓        |
+| Deflate  | ✓        | ✓        |
+| PackBits | ✓        | ✓        |
+| JPEG     | ✓        | not yet  |
+| ZSTD     | ✓        | not yet  |
+
+
+## Not yet supported
+
+Formats and interpretations not listed above or with empty entries are unsupported.
+
+- Baseline tags
+  - `ExtraSamples`
+- Extension tags
+
+## Fuzzing
+
+This crate uses [cargo-fuzz](https://github.com/rust-fuzz/cargo-fuzz) in order to test the image parser.
+
+After installing it with `cargo install cargo-fuzz` on a nightly rustc, the
+fuzzing harness can be run with recommended settings using 
+`cargo fuzz run decode_image -snone -- -timeout=5`.

benches/lzw.rs

@@ -0,0 +1,82 @@
+extern crate criterion;
+extern crate tiff;
+
+use criterion::{
+    black_box, measurement::Measurement, BenchmarkGroup, BenchmarkId, Criterion, Throughput,
+};
+use tiff::decoder::Decoder;
+
+fn read_image(image: &[u8]) {
+    let image = std::io::Cursor::new(image);
+    let decoder = Decoder::new(black_box(image));
+    let mut reader = decoder.unwrap();
+
+    while {
+        reader.read_image().unwrap();
+        reader.more_images()
+    } {}
+}
+
+fn main() {
+    struct BenchDef {
+        data: &'static [u8],
+        id: &'static str,
+        sample_size: usize,
+    }
+
+    fn run_bench_def<M: Measurement>(group: &mut BenchmarkGroup<M>, def: BenchDef) {
+        group
+            .sample_size(def.sample_size)
+            .throughput(Throughput::Bytes(def.data.len() as u64))
+            .bench_with_input(
+                BenchmarkId::new(def.id, def.data.len()),
+                def.data,
+                |b, input| b.iter(|| read_image(input)),
+            );
+    }
+
+    let mut c = Criterion::default().configure_from_args();
+    let mut group = c.benchmark_group("tiff-lzw");
+
+    macro_rules! data_file {
+        ($name:literal) => {
+            include_bytes!(concat!(env!("CARGO_MANIFEST_DIR"), $name))
+        };
+    }
+
+    run_bench_def(
+        &mut group,
+        BenchDef {
+            data: data_file!("/tests/images/issue_69_lzw.tiff"),
+            id: "issue-69-lzw.tif",
+            sample_size: 500,
+        },
+    );
+
+    run_bench_def(
+        &mut group,
+        BenchDef {
+            data: data_file!("/tests/benches/kodim02-lzw.tif"),
+            id: "kodim02-lzw.tif",
+            sample_size: 20,
+        },
+    );
+
+    run_bench_def(
+        &mut group,
+        BenchDef {
+            data: data_file!("/tests/benches/kodim07-lzw.tif"),
+            id: "kodim07-lzw.tif",
+            sample_size: 20,
+        },
+    );
+
+    run_bench_def(
+        &mut group,
+        BenchDef {
+            data: data_file!("/tests/benches/Transparency-lzw.tif"),
+            id: "Transparency-lzw.tif",
+            sample_size: 20,
+        },
+    );
+}

fuzz/.gitignore

@@ -0,0 +1,3 @@
+target
+corpus
+artifacts

fuzz/Cargo.toml

@@ -0,0 +1,25 @@
+[package]
+name = "tiff-fuzz"
+version = "0.0.0"
+authors = ["Automatically generated"]
+publish = false
+edition = "2018"
+
+[package.metadata]
+cargo-fuzz = true
+
+[dependencies]
+libfuzzer-sys = "0.4"
+
+[dependencies.tiff]
+path = ".."
+
+# Prevent this from interfering with workspaces
+[workspace]
+members = ["."]
+
+[[bin]]
+name = "decode_image"
+path = "fuzz_targets/decode_image.rs"
+test = false
+doc = false

fuzz/fuzz_targets/decode_image.rs

@@ -0,0 +1,31 @@
+#![no_main]
+use libfuzzer_sys::fuzz_target;
+
+fuzz_target!(|data: &[u8]| {
+    let mut decoder = if let Ok(d) = tiff::decoder::Decoder::new(std::io::Cursor::new(data)) {
+        d
+    } else {
+        return;
+    };
+
+    let mut limits = tiff::decoder::Limits::default();
+    limits.decoding_buffer_size = 1_000_000;
+    limits.ifd_value_size = 1_000_000;
+    limits.intermediate_buffer_size = 1_000_000;
+
+    decoder = decoder.with_limits(limits);
+    
+    loop {
+        if let Err(_) = decoder.read_image() {
+            break;
+        }
+
+        if !decoder.more_images() {
+            break;
+        }
+
+        if let Err(_) = decoder.next_image() {
+            break;
+        }
+    }
+});

src/bytecast.rs

@@ -0,0 +1,37 @@
+//! Trivial, internal byte transmutation.
+//!
+//! A dependency like bytemuck would give us extra assurance of the safety but overall would not
+//! reduce the amount of total unsafety. We don't use it in the interface where the traits would
+//! really become useful.
+//!
+//! SAFETY: These are benign casts as we apply them to fixed size integer types only. All of them
+//! are naturally aligned, valid for all bit patterns and their alignment is surely at most their
+//! size (we assert the latter fact since it is 'implementation defined' if following the letter of
+//! the unsafe code guidelines).
+//!
+//! TODO: Would like to use std-lib here.
+use std::{mem, slice};
+
+use half::f16;
+
+macro_rules! integral_slice_as_bytes{($int:ty, $const:ident $(,$mut:ident)*) => {
+    pub(crate) fn $const(slice: &[$int]) -> &[u8] {
+        assert!(mem::align_of::<$int>() <= mem::size_of::<$int>());
+        unsafe { slice::from_raw_parts(slice.as_ptr() as *const u8, mem::size_of_val(slice)) }
+    }
+    $(pub(crate) fn $mut(slice: &mut [$int]) -> &mut [u8] {
+        assert!(mem::align_of::<$int>() <= mem::size_of::<$int>());
+        unsafe { slice::from_raw_parts_mut(slice.as_mut_ptr() as *mut u8, mem::size_of_val(slice)) }
+    })*
+}}
+
+integral_slice_as_bytes!(i8, i8_as_ne_bytes, i8_as_ne_mut_bytes);
+integral_slice_as_bytes!(u16, u16_as_ne_bytes, u16_as_ne_mut_bytes);
+integral_slice_as_bytes!(i16, i16_as_ne_bytes, i16_as_ne_mut_bytes);
+integral_slice_as_bytes!(u32, u32_as_ne_bytes, u32_as_ne_mut_bytes);
+integral_slice_as_bytes!(i32, i32_as_ne_bytes, i32_as_ne_mut_bytes);
+integral_slice_as_bytes!(u64, u64_as_ne_bytes, u64_as_ne_mut_bytes);
+integral_slice_as_bytes!(i64, i64_as_ne_bytes, i64_as_ne_mut_bytes);
+integral_slice_as_bytes!(f32, f32_as_ne_bytes, f32_as_ne_mut_bytes);
+integral_slice_as_bytes!(f16, f16_as_ne_bytes, f16_as_ne_mut_bytes);
+integral_slice_as_bytes!(f64, f64_as_ne_bytes, f64_as_ne_mut_bytes);

src/decoder/cycles.rs

@@ -0,0 +1,169 @@
+use crate::{tags::IfdPointer, TiffError, TiffFormatError};
+use std::collections::HashMap;
+
+/// The IFD structure of a TIFF file should be limited to a forest of entries, and a tree when we
+/// only consider having a primary IFD and its children. There is up to one primary child of a node
+/// that is the `next` entry in an IFD itself. Since we offer iteration over this chain we want to
+/// detect when a new edge would introduce a cycle, such that callers can be guaranteed to
+/// terminate iteration at some point even in malicious images.
+///
+/// However, we are not necessarily visiting the IFDs in their topological order.
+///
+/// Since we only consider one child, we run union find to assign each pointer to a known chain.
+/// Then, when we insert a new edge we check if they belong to the same component.
+#[derive(Default, Debug)]
+pub struct IfdCycles {
+    /// The root of each component union.
+    component_union: HashMap<ComponentId, ComponentId>,
+    links: HashMap<IfdPointer, u64>,
+    chains: HashMap<IfdPointer, ComponentId>,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+struct ComponentId(u64);
+
+impl IfdCycles {
+    pub fn new() -> Self {
+        IfdCycles::default()
+    }
+
+    pub fn insert_next(
+        &mut self,
+        from: IfdPointer,
+        to: Option<IfdPointer>,
+    ) -> Result<bool, TiffError> {
+        let to_offset = to.map_or(0, |p| p.0);
+
+        // For some reason we got
+        match self.links.get(&from) {
+            Some(existing) if *existing == to_offset => return Ok(false),
+            // We got here twice with two different reads of the same IFD. That is .. unusual and
+            // we interpret it as a cycle.
+            Some(_) => return Err(TiffError::FormatError(TiffFormatError::CycleInOffsets)),
+            None => self.links.insert(from, to_offset),
+        };
+
+        self.ensure_node(from);
+
+        if let Some(to) = to {
+            self.ensure_node(to);
+
+            let parent = self.nominal_component(from);
+            let child = self.nominal_component(to);
+
+            if parent == child {
+                return Err(TiffError::FormatError(TiffFormatError::CycleInOffsets));
+            }
+
+            self.component_union.insert(child, parent);
+        }
+
+        Ok(true)
+    }
+
+    fn ensure_node(&mut self, ifd: IfdPointer) {
+        self.chains.entry(ifd).or_insert_with(|| {
+            let id = ComponentId(self.component_union.len() as u64);
+            self.component_union.insert(id, id);
+            id
+        });
+    }
+
+    fn nominal_component(&mut self, node: IfdPointer) -> ComponentId {
+        let id = self.chains[&node];
+
+        let nomimal = {
+            let mut iter = id;
+
+            loop {
+                let parent = self.component_union[&iter];
+
+                if parent == iter {
+                    break parent;
+                }
+
+                iter = parent;
+            }
+        };
+
+        if nomimal != id {
+            // Compress.
+            let mut iter = id;
+
+            loop {
+                let parent = self.component_union[&iter];
+
+                if parent == iter {
+                    break;
+                }
+
+                self.component_union.insert(iter, nomimal);
+                iter = parent;
+            }
+        }
+
+        nomimal
+    }
+}
+
+#[test]
+fn cycles_are_detected() {
+    let mut cycles = IfdCycles::new();
+
+    cycles
+        .insert_next(IfdPointer(0x20), Some(IfdPointer(0x800)))
+        .expect("non-existing link is valid");
+
+    cycles
+        .insert_next(IfdPointer(0x800), Some(IfdPointer(0x20)))
+        .expect_err("cycle must be detected");
+}
+
+#[test]
+fn reflective_cycle() {
+    let mut cycles = IfdCycles::new();
+
+    cycles
+        .insert_next(IfdPointer(0x20), Some(IfdPointer(0x20)))
+        .expect_err("self-referential cycle must be detected");
+}
+
+#[test]
+fn late_cycle() {
+    let mut cycles = IfdCycles::new();
+
+    cycles
+        .insert_next(IfdPointer(0x20), Some(IfdPointer(0x40)))
+        .expect("non-existing link is valid");
+
+    cycles
+        .insert_next(IfdPointer(0x60), Some(IfdPointer(0x80)))
+        .expect("non-existing link is valid");
+    cycles
+        .insert_next(IfdPointer(0x80), Some(IfdPointer(0x20)))
+        .expect("non-existing link is valid");
+
+    cycles
+        .insert_next(IfdPointer(0x40), Some(IfdPointer(0x60)))
+        .expect_err("non-existing link is valid");
+}
+
+#[test]
+fn odd_cycle() {
+    let mut cycles = IfdCycles::new();
+
+    cycles
+        .insert_next(IfdPointer(0x20), Some(IfdPointer(0x40)))
+        .expect("non-existing link is valid");
+
+    cycles
+        .insert_next(IfdPointer(0x60), Some(IfdPointer(0x80)))
+        .expect("non-existing link is valid");
+    cycles
+        .insert_next(IfdPointer(0x80), Some(IfdPointer(0x20)))
+        .expect("non-existing link is valid");
+
+    cycles
+        .insert_next(IfdPointer(0x40), Some(IfdPointer(0x80)))
+        .expect_err("non-existing link is valid");
+}

src/decoder/ifd.rs

@@ -3,168 +3,156 @@
 use std::collections::HashMap;
 use std::io::{self, Read, Seek};
 use std::mem;
+use std::str;
 
-use super::stream::{ByteOrder, EndianReader, SmartReader};
-use {TiffError, TiffFormatError, TiffResult, TiffUnsupportedError};
-
-use self::Value::{Ascii, List, Rational, Unsigned, Signed, SRational};
-
-macro_rules! tags {
-    {
-        // Permit arbitrary meta items, which include documentation.
-        $( #[$enum_attr:meta] )*
-        $vis:vis enum $name:ident($ty:ty) $(unknown($unknown_doc:literal))* {
-            // Each of the `Name = Val,` permitting documentation.
-            $($(#[$ident_attr:meta])* $tag:ident = $val:expr,)*
-        }
-    } => {
-        $( #[$enum_attr] )*
-        #[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
-        pub enum $name {
-            $($(#[$ident_attr])* $tag,)*
-            // FIXME: switch to non_exhaustive once stabilized and compiler requirement new enough
-            #[doc(hidden)]
-            __NonExhaustive,
-            $( 
-                #[doc = $unknown_doc]
-                Unknown($ty),
-            )*
-        }
-
-        impl $name {
-            #[inline(always)]
-            fn __from_inner_type(n: $ty) -> Result<Self, $ty> {
-                match n {
-                    $( $val => Ok($name::$tag), )*
-                    n => Err(n),
-                }
-            }
-
-            #[inline(always)]
-            fn __to_inner_type(&self) -> $ty {
-                match *self {
-                    $( $name::$tag => $val, )*
-                    $( $name::Unknown(n) => { $unknown_doc; n }, )*
-                    $name::__NonExhaustive => unreachable!(),
-                }
-            }
-        }
-    }
-}
-
-// Note: These tags appear in the order they are mentioned in the TIFF reference
-tags! {
-/// TIFF tags
-pub enum Tag(u16) unknown("A private or extension tag") {
-    // Baseline tags:
-    Artist = 315,
-    // grayscale images PhotometricInterpretation 1 or 3
-    BitsPerSample = 258,
-    CellLength = 265, // TODO add support
-    CellWidth = 264, // TODO add support
-    // palette-color images (PhotometricInterpretation 3)
-    ColorMap = 320, // TODO add support
-    Compression = 259, // TODO add support for 2 and 32773
-    Copyright = 33_432,
-    DateTime = 306,
-    ExtraSamples = 338, // TODO add support
-    FillOrder = 266, // TODO add support
-    FreeByteCounts = 289, // TODO add support
-    FreeOffsets = 288, // TODO add support
-    GrayResponseCurve = 291, // TODO add support
-    GrayResponseUnit = 290, // TODO add support
-    HostComputer = 316,
-    ImageDescription = 270,
-    ImageLength = 257,
-    ImageWidth = 256,
-    Make = 271,
-    MaxSampleValue = 281, // TODO add support
-    MinSampleValue = 280, // TODO add support
-    Model = 272,
-    NewSubfileType = 254, // TODO add support
-    Orientation = 274, // TODO add support
-    PhotometricInterpretation = 262,
-    PlanarConfiguration = 284,
-    ResolutionUnit = 296, // TODO add support
-    RowsPerStrip = 278,
-    SamplesPerPixel = 277,
-    Software = 305,
-    StripByteCounts = 279,
-    StripOffsets = 273,
-    SubfileType = 255, // TODO add support
-    Threshholding = 263, // TODO add support
-    XResolution = 282,
-    YResolution = 283,
-    // Advanced tags
-    Predictor = 317,
-}
-}
-
-impl Tag {
-    pub fn from_u16(val: u16) -> Self {
-        Self::__from_inner_type(val).unwrap_or_else(Tag::Unknown)
-    }
-
-    pub fn to_u16(&self) -> u16 {
-        Self::__to_inner_type(self)
-    }
-}
-
-tags! {
-/// The type of an IFD entry (a 2 byte field).
-pub enum Type(u16) {
-    BYTE = 1,
-    ASCII = 2,
-    SHORT = 3,
-    LONG = 4,
-    RATIONAL = 5,
-    SBYTE = 6,
-    SSHORT = 8,
-    SLONG = 9,
-    SRATIONAL = 10,
-}
-}
-
-impl Type {
-    pub fn from_u16(val: u16) -> Option<Self> {
-        Self::__from_inner_type(val).ok()
-    }
-
-    pub fn to_u16(&self) -> u16 {
-        Self::__to_inner_type(self)
-    }
-}
+use super::stream::{ByteOrder, EndianReader};
+use crate::tags::{IfdPointer, Tag, Type};
+use crate::{TiffError, TiffFormatError, TiffResult};
 
+use self::Value::{
+    Ascii, Byte, Double, Float, Ifd, IfdBig, List, Rational, RationalBig, SRational, SRationalBig,
+    Short, Signed, SignedBig, SignedByte, SignedShort, Unsigned, UnsignedBig,
+};
 
 #[allow(unused_qualifications)]
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, PartialEq)]
+#[non_exhaustive]
 pub enum Value {
+    Byte(u8),
+    Short(u16),
+    SignedByte(i8),
+    SignedShort(i16),
     Signed(i32),
+    SignedBig(i64),
     Unsigned(u32),
+    UnsignedBig(u64),
+    Float(f32),
+    Double(f64),
     List(Vec<Value>),
     Rational(u32, u32),
+    RationalBig(u64, u64),
     SRational(i32, i32),
+    SRationalBig(i64, i64),
     Ascii(String),
-    #[doc(hidden)] // Do not match against this.
-    __NonExhaustive,
+    Ifd(u32),
+    IfdBig(u64),
 }
 
 impl Value {
+    pub fn into_u8(self) -> TiffResult<u8> {
+        match self {
+            Byte(val) => Ok(val),
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
+        }
+    }
+    pub fn into_i8(self) -> TiffResult<i8> {
+        match self {
+            SignedByte(val) => Ok(val),
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
+        }
+    }
+
+    pub fn into_u16(self) -> TiffResult<u16> {
+        match self {
+            Byte(val) => Ok(val.into()),
+            Short(val) => Ok(val),
+            Unsigned(val) => Ok(u16::try_from(val)?),
+            UnsignedBig(val) => Ok(u16::try_from(val)?),
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
+        }
+    }
+
+    pub fn into_i16(self) -> TiffResult<i16> {
+        match self {
+            SignedByte(val) => Ok(val.into()),
+            SignedShort(val) => Ok(val),
+            Signed(val) => Ok(i16::try_from(val)?),
+            SignedBig(val) => Ok(i16::try_from(val)?),
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
+        }
+    }
+
     pub fn into_u32(self) -> TiffResult<u32> {
         match self {
+            Byte(val) => Ok(val.into()),
+            Short(val) => Ok(val.into()),
             Unsigned(val) => Ok(val),
-            val => Err(TiffError::FormatError(
-                TiffFormatError::UnsignedIntegerExpected(val),
-            )),
+            UnsignedBig(val) => Ok(u32::try_from(val)?),
+            Ifd(val) => Ok(val),
+            IfdBig(val) => Ok(u32::try_from(val)?),
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
         }
     }
 
     pub fn into_i32(self) -> TiffResult<i32> {
         match self {
+            SignedByte(val) => Ok(val.into()),
+            SignedShort(val) => Ok(val.into()),
             Signed(val) => Ok(val),
-            val => Err(TiffError::FormatError(
-                TiffFormatError::SignedIntegerExpected(val),
-            )),
+            SignedBig(val) => Ok(i32::try_from(val)?),
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
+        }
+    }
+
+    pub fn into_u64(self) -> TiffResult<u64> {
+        match self {
+            Byte(val) => Ok(val.into()),
+            Short(val) => Ok(val.into()),
+            Unsigned(val) => Ok(val.into()),
+            UnsignedBig(val) => Ok(val),
+            Ifd(val) => Ok(val.into()),
+            IfdBig(val) => Ok(val),
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
+        }
+    }
+
+    pub fn into_i64(self) -> TiffResult<i64> {
+        match self {
+            SignedByte(val) => Ok(val.into()),
+            SignedShort(val) => Ok(val.into()),
+            Signed(val) => Ok(val.into()),
+            SignedBig(val) => Ok(val),
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
+        }
+    }
+
+    pub fn into_f32(self) -> TiffResult<f32> {
+        match self {
+            Float(val) => Ok(val),
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
+        }
+    }
+
+    pub fn into_f64(self) -> TiffResult<f64> {
+        match self {
+            Double(val) => Ok(val),
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
+        }
+    }
+
+    /// Turn this value into an `IfdPointer`.
+    ///
+    /// Notice that this does not take an argument, a 64-bit IFD is always allowed. If the
+    /// difference is crucial and you do not want to be permissive you're expected to filter this
+    /// out before.
+    ///
+    /// For compatibility the smaller sized tags should always be allowed i.e. you might use a
+    /// non-bigtiff's directory and its tag types and move it straight to a bigtiff. For instance
+    /// the SubIFD tag is defined as `LONG or IFD`:
+    ///
+    /// <https://web.archive.org/web/20181105221012/https://www.awaresystems.be/imaging/tiff/tifftags/subifds.html>
+    pub fn into_ifd_pointer(self) -> TiffResult<IfdPointer> {
+        match self {
+            Unsigned(val) | Ifd(val) => Ok(IfdPointer(val.into())),
+            IfdBig(val) => Ok(IfdPointer(val)),
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
+        }
+    }
+
+    pub fn into_string(self) -> TiffResult<String> {
+        match self {
+            Ascii(val) => Ok(val),
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
         }
     }
 
@@ -177,12 +165,48 @@ impl Value {
                 }
                 Ok(new_vec)
             }
+            Byte(val) => Ok(vec![val.into()]),
+            Short(val) => Ok(vec![val.into()]),
             Unsigned(val) => Ok(vec![val]),
+            UnsignedBig(val) => Ok(vec![u32::try_from(val)?]),
             Rational(numerator, denominator) => Ok(vec![numerator, denominator]),
-            Ascii(val) => Ok(val.chars().map(|x| x as u32).collect()),
-            val => Err(TiffError::FormatError(
-                TiffFormatError::UnsignedIntegerExpected(val),
-            )),
+            RationalBig(numerator, denominator) => {
+                Ok(vec![u32::try_from(numerator)?, u32::try_from(denominator)?])
+            }
+            Ifd(val) => Ok(vec![val]),
+            IfdBig(val) => Ok(vec![u32::try_from(val)?]),
+            Ascii(val) => Ok(val.chars().map(u32::from).collect()),
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
+        }
+    }
+
+    pub fn into_u8_vec(self) -> TiffResult<Vec<u8>> {
+        match self {
+            List(vec) => {
+                let mut new_vec = Vec::with_capacity(vec.len());
+                for v in vec {
+                    new_vec.push(v.into_u8()?)
+                }
+                Ok(new_vec)
+            }
+            Byte(val) => Ok(vec![val]),
+
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
+        }
+    }
+
+    pub fn into_u16_vec(self) -> TiffResult<Vec<u16>> {
+        match self {
+            List(vec) => {
+                let mut new_vec = Vec::with_capacity(vec.len());
+                for v in vec {
+                    new_vec.push(v.into_u16()?)
+                }
+                Ok(new_vec)
+            }
+            Byte(val) => Ok(vec![val.into()]),
+            Short(val) => Ok(vec![val]),
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
         }
     }
 
@@ -196,25 +220,123 @@ impl Value {
                             new_vec.push(numerator);
                             new_vec.push(denominator);
                         }
-                        _ => new_vec.push(v.into_i32()?)
+                        SRationalBig(numerator, denominator) => {
+                            new_vec.push(i32::try_from(numerator)?);
+                            new_vec.push(i32::try_from(denominator)?);
+                        }
+                        _ => new_vec.push(v.into_i32()?),
                     }
                 }
                 Ok(new_vec)
             }
+            SignedByte(val) => Ok(vec![val.into()]),
+            SignedShort(val) => Ok(vec![val.into()]),
             Signed(val) => Ok(vec![val]),
+            SignedBig(val) => Ok(vec![i32::try_from(val)?]),
             SRational(numerator, denominator) => Ok(vec![numerator, denominator]),
-            val => Err(TiffError::FormatError(
-                TiffFormatError::SignedIntegerExpected(val),
-            )),
+            SRationalBig(numerator, denominator) => {
+                Ok(vec![i32::try_from(numerator)?, i32::try_from(denominator)?])
+            }
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
         }
     }
+
+    pub fn into_f32_vec(self) -> TiffResult<Vec<f32>> {
+        match self {
+            List(vec) => {
+                let mut new_vec = Vec::with_capacity(vec.len());
+                for v in vec {
+                    new_vec.push(v.into_f32()?)
+                }
+                Ok(new_vec)
+            }
+            Float(val) => Ok(vec![val]),
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
+        }
+    }
+
+    pub fn into_f64_vec(self) -> TiffResult<Vec<f64>> {
+        match self {
+            List(vec) => {
+                let mut new_vec = Vec::with_capacity(vec.len());
+                for v in vec {
+                    new_vec.push(v.into_f64()?)
+                }
+                Ok(new_vec)
+            }
+            Double(val) => Ok(vec![val]),
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
+        }
+    }
+
+    pub fn into_u64_vec(self) -> TiffResult<Vec<u64>> {
+        match self {
+            List(vec) => {
+                let mut new_vec = Vec::with_capacity(vec.len());
+                for v in vec {
+                    new_vec.push(v.into_u64()?)
+                }
+                Ok(new_vec)
+            }
+            Byte(val) => Ok(vec![val.into()]),
+            Short(val) => Ok(vec![val.into()]),
+            Unsigned(val) => Ok(vec![val.into()]),
+            UnsignedBig(val) => Ok(vec![val]),
+            Rational(numerator, denominator) => Ok(vec![numerator.into(), denominator.into()]),
+            RationalBig(numerator, denominator) => Ok(vec![numerator, denominator]),
+            Ifd(val) => Ok(vec![val.into()]),
+            IfdBig(val) => Ok(vec![val]),
+            Ascii(val) => Ok(val.chars().map(u32::from).map(u64::from).collect()),
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
+        }
+    }
+
+    pub fn into_i64_vec(self) -> TiffResult<Vec<i64>> {
+        match self {
+            List(vec) => {
+                let mut new_vec = Vec::with_capacity(vec.len());
+                for v in vec {
+                    match v {
+                        SRational(numerator, denominator) => {
+                            new_vec.push(numerator.into());
+                            new_vec.push(denominator.into());
+                        }
+                        SRationalBig(numerator, denominator) => {
+                            new_vec.push(numerator);
+                            new_vec.push(denominator);
+                        }
+                        _ => new_vec.push(v.into_i64()?),
+                    }
+                }
+                Ok(new_vec)
+            }
+            SignedByte(val) => Ok(vec![val.into()]),
+            SignedShort(val) => Ok(vec![val.into()]),
+            Signed(val) => Ok(vec![val.into()]),
+            SignedBig(val) => Ok(vec![val]),
+            SRational(numerator, denominator) => Ok(vec![numerator.into(), denominator.into()]),
+            SRationalBig(numerator, denominator) => Ok(vec![numerator, denominator]),
+            _ => Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
+        }
+    }
+
+    pub fn into_ifd_vec(self) -> TiffResult<Vec<IfdPointer>> {
+        let vec = match self {
+            Unsigned(val) | Ifd(val) => return Ok(vec![IfdPointer(val.into())]),
+            IfdBig(val) => return Ok(vec![IfdPointer(val)]),
+            List(vec) => vec,
+            _ => return Err(TiffError::FormatError(TiffFormatError::InvalidTypeForTag)),
+        };
+
+        vec.into_iter().map(Self::into_ifd_pointer).collect()
+    }
 }
 
 #[derive(Clone)]
 pub struct Entry {
     type_: Type,
-    count: u32,
-    offset: [u8; 4],
+    count: u64,
+    offset: [u8; 8],
 }
 
 impl ::std::fmt::Debug for Entry {
@@ -228,6 +350,12 @@ impl ::std::fmt::Debug for Entry {
 
 impl Entry {
     pub fn new(type_: Type, count: u32, offset: [u8; 4]) -> Entry {
+        let mut entry_off = [0u8; 8];
+        entry_off[..4].copy_from_slice(&offset);
+        Entry::new_u64(type_, count.into(), entry_off)
+    }
+
+    pub fn new_u64(type_: Type, count: u64, offset: [u8; 8]) -> Entry {
         Entry {
             type_,
             count,
@@ -235,116 +363,325 @@ impl Entry {
         }
     }
 
-    /// Returns a mem_reader for the offset/value field
-    fn r(&self, byte_order: ByteOrder) -> SmartReader<io::Cursor<Vec<u8>>> {
-        SmartReader::wrap(io::Cursor::new(self.offset.to_vec()), byte_order)
+    pub fn field_type(&self) -> Type {
+        self.type_
     }
 
-    pub fn val<R: Read + Seek>(
+    pub fn count(&self) -> u64 {
+        self.count
+    }
+
+    pub(crate) fn offset(&self) -> &[u8] {
+        &self.offset
+    }
+
+    /// Returns a mem_reader for the offset/value field
+    fn r(&self, byte_order: ByteOrder) -> EndianReader<io::Cursor<Vec<u8>>> {
+        EndianReader::new(io::Cursor::new(self.offset.to_vec()), byte_order)
+    }
+
+    pub(crate) fn val<R: Read + Seek>(
         &self,
         limits: &super::Limits,
-        decoder: &mut super::Decoder<R>,
+        bigtiff: bool,
+        reader: &mut EndianReader<R>,
     ) -> TiffResult<Value> {
-        let bo = decoder.byte_order();
-        match (self.type_, self.count) {
+        // Case 1: there are no values so we can return immediately.
+        if self.count == 0 {
+            return Ok(List(Vec::new()));
+        }
+
+        let bo = reader.byte_order;
+
+        let tag_size = match self.type_ {
+            Type::BYTE | Type::SBYTE | Type::ASCII | Type::UNDEFINED => 1,
+            Type::SHORT | Type::SSHORT => 2,
+            Type::LONG | Type::SLONG | Type::FLOAT | Type::IFD => 4,
+            Type::LONG8
+            | Type::SLONG8
+            | Type::DOUBLE
+            | Type::RATIONAL
+            | Type::SRATIONAL
+            | Type::IFD8 => 8,
+        };
+
+        let value_bytes = match self.count.checked_mul(tag_size) {
+            Some(n) => n,
+            None => {
+                return Err(TiffError::LimitsExceeded);
+            }
+        };
+
+        // Case 2: there is one value.
+        if self.count == 1 {
+            // 2a: the value is 5-8 bytes and we're in BigTiff mode.
+            if bigtiff && value_bytes > 4 && value_bytes <= 8 {
+                return Ok(match self.type_ {
+                    Type::LONG8 => UnsignedBig(self.r(bo).read_u64()?),
+                    Type::SLONG8 => SignedBig(self.r(bo).read_i64()?),
+                    Type::DOUBLE => Double(self.r(bo).read_f64()?),
+                    Type::RATIONAL => {
+                        let mut r = self.r(bo);
+                        Rational(r.read_u32()?, r.read_u32()?)
+                    }
+                    Type::SRATIONAL => {
+                        let mut r = self.r(bo);
+                        SRational(r.read_i32()?, r.read_i32()?)
+                    }
+                    Type::IFD8 => IfdBig(self.r(bo).read_u64()?),
+                    Type::BYTE
+                    | Type::SBYTE
+                    | Type::ASCII
+                    | Type::UNDEFINED
+                    | Type::SHORT
+                    | Type::SSHORT
+                    | Type::LONG
+                    | Type::SLONG
+                    | Type::FLOAT
+                    | Type::IFD => unreachable!(),
+                });
+            }
+
+            // 2b: the value is at most 4 bytes or doesn't fit in the offset field.
+            return Ok(match self.type_ {
+                Type::BYTE => Byte(self.offset[0]),
+                Type::SBYTE => SignedByte(i8::from(self.offset[0] as i8)),
+                Type::UNDEFINED => Byte(self.offset[0]),
+                Type::SHORT => Short(self.r(bo).read_u16()?),
+                Type::SSHORT => SignedShort(self.r(bo).read_i16()?),
+                Type::LONG => Unsigned(self.r(bo).read_u32()?),
+                Type::SLONG => Signed(self.r(bo).read_i32()?),
+                Type::FLOAT => Float(self.r(bo).read_f32()?),
+                Type::ASCII => {
+                    if self.offset[0] == 0 {
+                        Ascii("".to_string())
+                    } else {
+                        return Err(TiffError::FormatError(TiffFormatError::InvalidTag));
+                    }
+                }
+                Type::LONG8 => {
+                    reader.goto_offset(self.r(bo).read_u32()?.into())?;
+                    UnsignedBig(reader.read_u64()?)
+                }
+                Type::SLONG8 => {
+                    reader.goto_offset(self.r(bo).read_u32()?.into())?;
+                    SignedBig(reader.read_i64()?)
+                }
+                Type::DOUBLE => {
+                    reader.goto_offset(self.r(bo).read_u32()?.into())?;
+                    Double(reader.read_f64()?)
+                }
+                Type::RATIONAL => {
+                    reader.goto_offset(self.r(bo).read_u32()?.into())?;
+                    Rational(reader.read_u32()?, reader.read_u32()?)
+                }
+                Type::SRATIONAL => {
+                    reader.goto_offset(self.r(bo).read_u32()?.into())?;
+                    SRational(reader.read_i32()?, reader.read_i32()?)
+                }
+                Type::IFD => Ifd(self.r(bo).read_u32()?),
+                Type::IFD8 => {
+                    reader.goto_offset(self.r(bo).read_u32()?.into())?;
+                    IfdBig(reader.read_u64()?)
+                }
+            });
+        }
+
+        // Case 3: There is more than one value, but it fits in the offset field.
+        if value_bytes <= 4 || bigtiff && value_bytes <= 8 {
+            match self.type_ {
+                Type::BYTE => return offset_to_bytes(self.count as usize, self),
+                Type::SBYTE => return offset_to_sbytes(self.count as usize, self),
+                Type::ASCII => {
+                    let mut buf = vec![0; self.count as usize];
+                    buf.copy_from_slice(&self.offset[..self.count as usize]);
+                    if buf.is_ascii() && buf.ends_with(&[0]) {
+                        let v = str::from_utf8(&buf)?;
+                        let v = v.trim_matches(char::from(0));
+                        return Ok(Ascii(v.into()));
+                    } else {
+                        return Err(TiffError::FormatError(TiffFormatError::InvalidTag));
+                    }
+                }
+                Type::UNDEFINED => {
+                    return Ok(List(
+                        self.offset[0..self.count as usize]
+                            .iter()
+                            .map(|&b| Byte(b))
+                            .collect(),
+                    ));
+                }
+                Type::SHORT => {
+                    let mut r = self.r(bo);
+                    let mut v = Vec::new();
+                    for _ in 0..self.count {
+                        v.push(Short(r.read_u16()?));
+                    }
+                    return Ok(List(v));
+                }
+                Type::SSHORT => {
+                    let mut r = self.r(bo);
+                    let mut v = Vec::new();
+                    for _ in 0..self.count {
+                        v.push(SignedShort(r.read_i16()?));
+                    }
+                    return Ok(List(v));
+                }
+                Type::LONG => {
+                    let mut r = self.r(bo);
+                    let mut v = Vec::new();
+                    for _ in 0..self.count {
+                        v.push(Unsigned(r.read_u32()?));
+                    }
+                    return Ok(List(v));
+                }
+                Type::SLONG => {
+                    let mut r = self.r(bo);
+                    let mut v = Vec::new();
+                    for _ in 0..self.count {
+                        v.push(Signed(r.read_i32()?));
+                    }
+                    return Ok(List(v));
+                }
+                Type::FLOAT => {
+                    let mut r = self.r(bo);
+                    let mut v = Vec::new();
+                    for _ in 0..self.count {
+                        v.push(Float(r.read_f32()?));
+                    }
+                    return Ok(List(v));
+                }
+                Type::IFD => {
+                    let mut r = self.r(bo);
+                    let mut v = Vec::new();
+                    for _ in 0..self.count {
+                        v.push(Ifd(r.read_u32()?));
+                    }
+                    return Ok(List(v));
+                }
+                Type::LONG8
+                | Type::SLONG8
+                | Type::RATIONAL
+                | Type::SRATIONAL
+                | Type::DOUBLE
+                | Type::IFD8 => {
+                    unreachable!()
+                }
+            }
+        }
+
+        // Case 4: there is more than one value, and it doesn't fit in the offset field.
+        match self.type_ {
             // TODO check if this could give wrong results
             // at a different endianess of file/computer.
-            (Type::BYTE, 1) => Ok(Unsigned(u32::from(self.offset[0]))),
-            (Type::BYTE, 2) => offset_to_bytes(2, self),
-            (Type::BYTE, 3) => offset_to_bytes(3, self),
-            (Type::BYTE, 4) => offset_to_bytes(4, self),
-            (Type::BYTE, n) => self.decode_offset(n, bo, limits, decoder, |decoder| {
-                Ok(Unsigned(u32::from(decoder.read_byte()?)))
+            Type::BYTE => self.decode_offset(self.count, bo, bigtiff, limits, reader, |reader| {
+                let mut buf = [0; 1];
+                reader.inner().read_exact(&mut buf)?;
+                Ok(UnsignedBig(u64::from(buf[0])))
             }),
-            (Type::SBYTE, 1) => Ok(Signed(i32::from(self.offset[0] as i8))),
-            (Type::SBYTE, 2) => offset_to_sbytes(2, self),
-            (Type::SBYTE, 3) => offset_to_sbytes(3, self),
-            (Type::SBYTE, 4) => offset_to_sbytes(4, self),
-            (Type::SBYTE, n) => self.decode_offset(n, bo, limits, decoder, |decoder| {
-                Ok(Signed(i32::from(decoder.read_byte()? as i8)))
+            Type::SBYTE => self.decode_offset(self.count, bo, bigtiff, limits, reader, |reader| {
+                Ok(SignedBig(i64::from(reader.read_i8()?)))
             }),
-            (Type::SHORT, 1) => Ok(Unsigned(u32::from(self.r(bo).read_u16()?))),
-            (Type::SSHORT, 1) => Ok(Signed(i32::from(self.r(bo).read_i16()?))),
-            (Type::SHORT, 2) => {
-                let mut r = self.r(bo);
-                Ok(List(vec![
-                    Unsigned(u32::from(r.read_u16()?)),
-                    Unsigned(u32::from(r.read_u16()?)),
-                ]))
+            Type::SHORT => self.decode_offset(self.count, bo, bigtiff, limits, reader, |reader| {
+                Ok(Short(reader.read_u16()?))
+            }),
+            Type::SSHORT => self.decode_offset(self.count, bo, bigtiff, limits, reader, |reader| {
+                Ok(SignedShort(reader.read_i16()?))
+            }),
+            Type::LONG => self.decode_offset(self.count, bo, bigtiff, limits, reader, |reader| {
+                Ok(Unsigned(reader.read_u32()?))
+            }),
+            Type::SLONG => self.decode_offset(self.count, bo, bigtiff, limits, reader, |reader| {
+                Ok(Signed(reader.read_i32()?))
+            }),
+            Type::FLOAT => self.decode_offset(self.count, bo, bigtiff, limits, reader, |reader| {
+                Ok(Float(reader.read_f32()?))
+            }),
+            Type::DOUBLE => self.decode_offset(self.count, bo, bigtiff, limits, reader, |reader| {
+                Ok(Double(reader.read_f64()?))
+            }),
+            Type::RATIONAL => {
+                self.decode_offset(self.count, bo, bigtiff, limits, reader, |reader| {
+                    Ok(Rational(reader.read_u32()?, reader.read_u32()?))
+                })
             }
-            (Type::SSHORT, 2) => {
-                let mut r = self.r(bo);
-                Ok(List(vec![
-                    Signed(i32::from(r.read_i16()?)),
-                    Signed(i32::from(r.read_i16()?)),
-                ]))
+            Type::SRATIONAL => {
+                self.decode_offset(self.count, bo, bigtiff, limits, reader, |reader| {
+                    Ok(SRational(reader.read_i32()?, reader.read_i32()?))
+                })
             }
-            (Type::SHORT, n) => self.decode_offset(n, bo, limits, decoder, |decoder| {
-                Ok(Unsigned(u32::from(decoder.read_short()?)))
+            Type::LONG8 => self.decode_offset(self.count, bo, bigtiff, limits, reader, |reader| {
+                Ok(UnsignedBig(reader.read_u64()?))
             }),
-            (Type::SSHORT, n) => self.decode_offset(n, bo, limits, decoder, |decoder| {
-                Ok(Signed(i32::from(decoder.read_sshort()?)))
+            Type::SLONG8 => self.decode_offset(self.count, bo, bigtiff, limits, reader, |reader| {
+                Ok(SignedBig(reader.read_i64()?))
             }),
-            (Type::LONG, 1) => Ok(Unsigned(self.r(bo).read_u32()?)),
-            (Type::SLONG, 1) => Ok(Signed(self.r(bo).read_i32()?)),
-            (Type::LONG, n) => self.decode_offset(n, bo, limits, decoder, |decoder| {
-                Ok(Unsigned(decoder.read_long()?))
+            Type::IFD => self.decode_offset(self.count, bo, bigtiff, limits, reader, |reader| {
+                Ok(Ifd(reader.read_u32()?))
             }),
-            (Type::SLONG, n) => self.decode_offset(n, bo, limits, decoder, |decoder| {
-                Ok(Signed(decoder.read_slong()?))
+            Type::IFD8 => self.decode_offset(self.count, bo, bigtiff, limits, reader, |reader| {
+                Ok(IfdBig(reader.read_u64()?))
             }),
-            (Type::RATIONAL, 1) => {
-                decoder.goto_offset(self.r(bo).read_u32()?)?;
-                let numerator = decoder.read_long()?;
-                let denominator = decoder.read_long()?;
-                Ok(Rational(numerator, denominator))
+            Type::UNDEFINED => {
+                self.decode_offset(self.count, bo, bigtiff, limits, reader, |reader| {
+                    let mut buf = [0; 1];
+                    reader.inner().read_exact(&mut buf)?;
+                    Ok(Byte(buf[0]))
+                })
             }
-            (Type::SRATIONAL, 1) => {
-                decoder.goto_offset(self.r(bo).read_u32()?)?;
-                let numerator = decoder.read_slong()?;
-                let denominator = decoder.read_slong()?;
-                Ok(SRational(numerator, denominator))
-            }
-            (Type::RATIONAL, n) => self.decode_offset(n, bo, limits, decoder, |decoder| {
-                Ok(Rational(
-                    decoder.read_long()?,
-                    decoder.read_long()?,
-                ))
-            }),
-            (Type::SRATIONAL, n) => self.decode_offset(n, bo, limits, decoder, |decoder| {
-                Ok(SRational(
-                    decoder.read_slong()?,
-                    decoder.read_slong()?,
-                ))
-            }),
-            (Type::ASCII, n) => {
-                if n as usize > limits.decoding_buffer_size {
+            Type::ASCII => {
+                let n = usize::try_from(self.count)?;
+                if n > limits.decoding_buffer_size {
                     return Err(TiffError::LimitsExceeded);
                 }
-                decoder.goto_offset(self.r(bo).read_u32()?)?;
-                let string = decoder.read_string(n as usize)?;
-                Ok(Ascii(string))
+
+                if bigtiff {
+                    reader.goto_offset(self.r(bo).read_u64()?)?
+                } else {
+                    reader.goto_offset(self.r(bo).read_u32()?.into())?
+                }
+
+                let mut out = vec![0; n];
+                reader.inner().read_exact(&mut out)?;
+                // Strings may be null-terminated, so we trim anything downstream of the null byte
+                if let Some(first) = out.iter().position(|&b| b == 0) {
+                    out.truncate(first);
+                }
+                Ok(Ascii(String::from_utf8(out)?))
             }
-            _ => Err(TiffError::UnsupportedError(
-                TiffUnsupportedError::UnsupportedDataType,
-            )),
         }
     }
 
     #[inline]
-    fn decode_offset<R, F>(&self, value_count: u32, bo: ByteOrder, limits: &super::Limits, decoder: &mut super::Decoder<R>, decode_fn: F) -> TiffResult<Value>
-        where
-            R: Read + Seek,
-            F: Fn(&mut super::Decoder<R>) -> TiffResult<Value>,
+    fn decode_offset<R, F>(
+        &self,
+        value_count: u64,
+        bo: ByteOrder,
+        bigtiff: bool,
+        limits: &super::Limits,
+        reader: &mut EndianReader<R>,
+        decode_fn: F,
+    ) -> TiffResult<Value>
+    where
+        R: Read + Seek,
+        F: Fn(&mut EndianReader<R>) -> TiffResult<Value>,
     {
-        if value_count as usize > limits.decoding_buffer_size / mem::size_of::<Value>() {
+        let value_count = usize::try_from(value_count)?;
+        if value_count > limits.decoding_buffer_size / mem::size_of::<Value>() {
             return Err(TiffError::LimitsExceeded);
         }
 
-        let mut v = Vec::with_capacity(value_count as usize);
-        decoder.goto_offset(self.r(bo).read_u32()?)?;
+        let mut v = Vec::with_capacity(value_count);
+
+        let offset = if bigtiff {
+            self.r(bo).read_u64()?
+        } else {
+            self.r(bo).read_u32()?.into()
+        };
+        reader.goto_offset(offset)?;
+
         for _ in 0..value_count {
-            v.push(decode_fn(decoder)?)
+            v.push(decode_fn(reader)?)
         }
         Ok(List(v))
     }
@@ -357,7 +694,7 @@ fn offset_to_bytes(n: usize, entry: &Entry) -> TiffResult<Value> {
         entry.offset[0..n]
             .iter()
             .map(|&e| Unsigned(u32::from(e)))
-            .collect()
+            .collect(),
     ))
 }
 
@@ -368,9 +705,11 @@ fn offset_to_sbytes(n: usize, entry: &Entry) -> TiffResult<Value> {
         entry.offset[0..n]
             .iter()
             .map(|&e| Signed(i32::from(e as i8)))
-            .collect()
+            .collect(),
     ))
 }
 
 /// Type representing an Image File Directory
+#[doc(hidden)]
+#[deprecated = "Use struct `tiff::Directory` instead which contains all fields relevant to an Image File Directory, including the offset to the next directory"]
 pub type Directory = HashMap<Tag, Entry>;

src/decoder/image.rs

@@ -0,0 +1,710 @@
+use super::ifd::Value;
+use super::stream::PackBitsReader;
+use super::tag_reader::TagReader;
+use super::ChunkType;
+use super::{predict_f16, predict_f32, predict_f64, ValueReader};
+use crate::tags::{
+    CompressionMethod, PhotometricInterpretation, PlanarConfiguration, Predictor, SampleFormat, Tag,
+};
+use crate::{
+    ColorType, Directory, TiffError, TiffFormatError, TiffResult, TiffUnsupportedError, UsageError,
+};
+use std::io::{self, Cursor, Read, Seek};
+use std::sync::Arc;
+
+#[derive(Debug)]
+pub(crate) struct StripDecodeState {
+    pub rows_per_strip: u32,
+}
+
+#[derive(Debug)]
+/// Computed values useful for tile decoding
+pub(crate) struct TileAttributes {
+    pub image_width: usize,
+    pub image_height: usize,
+
+    pub tile_width: usize,
+    pub tile_length: usize,
+}
+
+impl TileAttributes {
+    pub fn tiles_across(&self) -> usize {
+        (self.image_width + self.tile_width - 1) / self.tile_width
+    }
+    pub fn tiles_down(&self) -> usize {
+        (self.image_height + self.tile_length - 1) / self.tile_length
+    }
+    fn padding_right(&self) -> usize {
+        (self.tile_width - self.image_width % self.tile_width) % self.tile_width
+    }
+    fn padding_down(&self) -> usize {
+        (self.tile_length - self.image_height % self.tile_length) % self.tile_length
+    }
+    pub fn get_padding(&self, tile: usize) -> (usize, usize) {
+        let row = tile / self.tiles_across();
+        let column = tile % self.tiles_across();
+
+        let padding_right = if column == self.tiles_across() - 1 {
+            self.padding_right()
+        } else {
+            0
+        };
+
+        let padding_down = if row == self.tiles_down() - 1 {
+            self.padding_down()
+        } else {
+            0
+        };
+
+        (padding_right, padding_down)
+    }
+}
+
+#[derive(Debug)]
+pub(crate) struct Image {
+    pub ifd: Option<Directory>,
+    pub width: u32,
+    pub height: u32,
+    pub bits_per_sample: u8,
+    pub samples: u16,
+    pub sample_format: SampleFormat,
+    pub photometric_interpretation: PhotometricInterpretation,
+    pub compression_method: CompressionMethod,
+    pub predictor: Predictor,
+    pub jpeg_tables: Option<Arc<Vec<u8>>>,
+    pub chunk_type: ChunkType,
+    pub planar_config: PlanarConfiguration,
+    pub strip_decoder: Option<StripDecodeState>,
+    pub tile_attributes: Option<TileAttributes>,
+    pub chunk_offsets: Vec<u64>,
+    pub chunk_bytes: Vec<u64>,
+}
+
+impl Image {
+    pub fn from_reader<R: Read + Seek>(
+        decoder: &mut ValueReader<R>,
+        ifd: Directory,
+    ) -> TiffResult<Image> {
+        let mut tag_reader = TagReader { decoder, ifd: &ifd };
+
+        let width = tag_reader.require_tag(Tag::ImageWidth)?.into_u32()?;
+        let height = tag_reader.require_tag(Tag::ImageLength)?.into_u32()?;
+        if width == 0 || height == 0 {
+            return Err(TiffError::FormatError(TiffFormatError::InvalidDimensions(
+                width, height,
+            )));
+        }
+
+        let photometric_interpretation = tag_reader
+            .find_tag(Tag::PhotometricInterpretation)?
+            .map(Value::into_u16)
+            .transpose()?
+            .and_then(PhotometricInterpretation::from_u16)
+            .ok_or(TiffUnsupportedError::UnknownInterpretation)?;
+
+        // Try to parse both the compression method and the number, format, and bits of the included samples.
+        // If they are not explicitly specified, those tags are reset to their default values and not carried from previous images.
+        let compression_method = match tag_reader.find_tag(Tag::Compression)? {
+            Some(val) => CompressionMethod::from_u16_exhaustive(val.into_u16()?),
+            None => CompressionMethod::None,
+        };
+
+        let jpeg_tables = if compression_method == CompressionMethod::ModernJPEG
+            && ifd.contains(Tag::JPEGTables)
+        {
+            let vec = tag_reader
+                .find_tag(Tag::JPEGTables)?
+                .unwrap()
+                .into_u8_vec()?;
+            if vec.len() < 2 {
+                return Err(TiffError::FormatError(
+                    TiffFormatError::InvalidTagValueType(Tag::JPEGTables),
+                ));
+            }
+
+            Some(Arc::new(vec))
+        } else {
+            None
+        };
+
+        let samples: u16 = tag_reader
+            .find_tag(Tag::SamplesPerPixel)?
+            .map(Value::into_u16)
+            .transpose()?
+            .unwrap_or(1);
+        if samples == 0 {
+            return Err(TiffFormatError::SamplesPerPixelIsZero.into());
+        }
+
+        let sample_format = match tag_reader.find_tag_uint_vec(Tag::SampleFormat)? {
+            Some(vals) => {
+                let sample_format: Vec<_> = vals
+                    .into_iter()
+                    .map(SampleFormat::from_u16_exhaustive)
+                    .collect();
+
+                // TODO: for now, only homogenous formats across samples are supported.
+                if !sample_format.windows(2).all(|s| s[0] == s[1]) {
+                    return Err(TiffUnsupportedError::UnsupportedSampleFormat(sample_format).into());
+                }
+
+                sample_format[0]
+            }
+            None => SampleFormat::Uint,
+        };
+
+        let bits_per_sample: Vec<u8> = tag_reader
+            .find_tag_uint_vec(Tag::BitsPerSample)?
+            .unwrap_or_else(|| vec![1]);
+
+        // Technically bits_per_sample.len() should be *equal* to samples, but libtiff also allows
+        // it to be a single value that applies to all samples.
+        if bits_per_sample.len() != samples.into() && bits_per_sample.len() != 1 {
+            return Err(TiffError::FormatError(
+                TiffFormatError::InconsistentSizesEncountered,
+            ));
+        }
+
+        // This library (and libtiff) do not support mixed sample formats and zero bits per sample
+        // doesn't make sense.
+        if bits_per_sample.iter().any(|&b| b != bits_per_sample[0]) || bits_per_sample[0] == 0 {
+            return Err(TiffUnsupportedError::InconsistentBitsPerSample(bits_per_sample).into());
+        }
+
+        let predictor = tag_reader
+            .find_tag(Tag::Predictor)?
+            .map(Value::into_u16)
+            .transpose()?
+            .map(|p| {
+                Predictor::from_u16(p)
+                    .ok_or(TiffError::FormatError(TiffFormatError::UnknownPredictor(p)))
+            })
+            .transpose()?
+            .unwrap_or(Predictor::None);
+
+        let planar_config = tag_reader
+            .find_tag(Tag::PlanarConfiguration)?
+            .map(Value::into_u16)
+            .transpose()?
+            .map(|p| {
+                PlanarConfiguration::from_u16(p).ok_or(TiffError::FormatError(
+                    TiffFormatError::UnknownPlanarConfiguration(p),
+                ))
+            })
+            .transpose()?
+            .unwrap_or(PlanarConfiguration::Chunky);
+
+        let planes = match planar_config {
+            PlanarConfiguration::Chunky => 1,
+            PlanarConfiguration::Planar => samples,
+        };
+
+        let chunk_type;
+        let chunk_offsets;
+        let chunk_bytes;
+        let strip_decoder;
+        let tile_attributes;
+        match (
+            ifd.contains(Tag::StripByteCounts),
+            ifd.contains(Tag::StripOffsets),
+            ifd.contains(Tag::TileByteCounts),
+            ifd.contains(Tag::TileOffsets),
+        ) {
+            (true, true, false, false) => {
+                chunk_type = ChunkType::Strip;
+
+                chunk_offsets = tag_reader
+                    .find_tag(Tag::StripOffsets)?
+                    .unwrap()
+                    .into_u64_vec()?;
+                chunk_bytes = tag_reader
+                    .find_tag(Tag::StripByteCounts)?
+                    .unwrap()
+                    .into_u64_vec()?;
+                let rows_per_strip = tag_reader
+                    .find_tag(Tag::RowsPerStrip)?
+                    .map(Value::into_u32)
+                    .transpose()?
+                    .unwrap_or(height);
+                strip_decoder = Some(StripDecodeState { rows_per_strip });
+                tile_attributes = None;
+
+                if chunk_offsets.len() != chunk_bytes.len()
+                    || rows_per_strip == 0
+                    || u32::try_from(chunk_offsets.len())?
+                        != (height.saturating_sub(1) / rows_per_strip + 1) * planes as u32
+                {
+                    return Err(TiffError::FormatError(
+                        TiffFormatError::InconsistentSizesEncountered,
+                    ));
+                }
+            }
+            (false, false, true, true) => {
+                chunk_type = ChunkType::Tile;
+
+                let tile_width =
+                    usize::try_from(tag_reader.require_tag(Tag::TileWidth)?.into_u32()?)?;
+                let tile_length =
+                    usize::try_from(tag_reader.require_tag(Tag::TileLength)?.into_u32()?)?;
+
+                if tile_width == 0 {
+                    return Err(TiffFormatError::InvalidTagValueType(Tag::TileWidth).into());
+                } else if tile_length == 0 {
+                    return Err(TiffFormatError::InvalidTagValueType(Tag::TileLength).into());
+                }
+
+                strip_decoder = None;
+                tile_attributes = Some(TileAttributes {
+                    image_width: usize::try_from(width)?,
+                    image_height: usize::try_from(height)?,
+                    tile_width,
+                    tile_length,
+                });
+                chunk_offsets = tag_reader
+                    .find_tag(Tag::TileOffsets)?
+                    .unwrap()
+                    .into_u64_vec()?;
+                chunk_bytes = tag_reader
+                    .find_tag(Tag::TileByteCounts)?
+                    .unwrap()
+                    .into_u64_vec()?;
+
+                let tile = tile_attributes.as_ref().unwrap();
+                if chunk_offsets.len() != chunk_bytes.len()
+                    || chunk_offsets.len()
+                        != tile.tiles_down() * tile.tiles_across() * planes as usize
+                {
+                    return Err(TiffError::FormatError(
+                        TiffFormatError::InconsistentSizesEncountered,
+                    ));
+                }
+            }
+            (_, _, _, _) => {
+                return Err(TiffError::FormatError(
+                    TiffFormatError::StripTileTagConflict,
+                ))
+            }
+        };
+
+        Ok(Image {
+            ifd: Some(ifd),
+            width,
+            height,
+            bits_per_sample: bits_per_sample[0],
+            samples,
+            sample_format,
+            photometric_interpretation,
+            compression_method,
+            jpeg_tables,
+            predictor,
+            chunk_type,
+            planar_config,
+            strip_decoder,
+            tile_attributes,
+            chunk_offsets,
+            chunk_bytes,
+        })
+    }
+
+    pub(crate) fn colortype(&self) -> TiffResult<ColorType> {
+        match self.photometric_interpretation {
+            PhotometricInterpretation::RGB => match self.samples {
+                3 => Ok(ColorType::RGB(self.bits_per_sample)),
+                4 => Ok(ColorType::RGBA(self.bits_per_sample)),
+                // FIXME: We should _ignore_ other components. In particular:
+                // > Beware of extra components. Some TIFF files may have more components per pixel
+                // than you think. A Baseline TIFF reader must skip over them gracefully,using the
+                // values of the SamplesPerPixel and BitsPerSample fields.
+                // > -- TIFF 6.0 Specification, Section 7, Additional Baseline requirements.
+                _ => Err(TiffError::UnsupportedError(
+                    TiffUnsupportedError::InterpretationWithBits(
+                        self.photometric_interpretation,
+                        vec![self.bits_per_sample; self.samples as usize],
+                    ),
+                )),
+            },
+            PhotometricInterpretation::CMYK => match self.samples {
+                4 => Ok(ColorType::CMYK(self.bits_per_sample)),
+                5 => Ok(ColorType::CMYKA(self.bits_per_sample)),
+                _ => Err(TiffError::UnsupportedError(
+                    TiffUnsupportedError::InterpretationWithBits(
+                        self.photometric_interpretation,
+                        vec![self.bits_per_sample; self.samples as usize],
+                    ),
+                )),
+            },
+            PhotometricInterpretation::YCbCr => match self.samples {
+                3 => Ok(ColorType::YCbCr(self.bits_per_sample)),
+                _ => Err(TiffError::UnsupportedError(
+                    TiffUnsupportedError::InterpretationWithBits(
+                        self.photometric_interpretation,
+                        vec![self.bits_per_sample; self.samples as usize],
+                    ),
+                )),
+            },
+            PhotometricInterpretation::BlackIsZero | PhotometricInterpretation::WhiteIsZero => {
+                match self.samples {
+                    1 => Ok(ColorType::Gray(self.bits_per_sample)),
+                    _ => Ok(ColorType::Multiband {
+                        bit_depth: self.bits_per_sample,
+                        num_samples: self.samples,
+                    }),
+                }
+            }
+            // TODO: this is bad we should not fail at this point
+            PhotometricInterpretation::RGBPalette
+            | PhotometricInterpretation::TransparencyMask
+            | PhotometricInterpretation::CIELab => Err(TiffError::UnsupportedError(
+                TiffUnsupportedError::InterpretationWithBits(
+                    self.photometric_interpretation,
+                    vec![self.bits_per_sample; self.samples as usize],
+                ),
+            )),
+        }
+    }
+
+    fn create_reader<'r, R: 'r + Read>(
+        reader: R,
+        compression_method: CompressionMethod,
+        compressed_length: u64,
+        #[allow(unused_variables)] jpeg_tables: Option<&[u8]>,
+    ) -> TiffResult<Box<dyn Read + 'r>> {
+        Ok(match compression_method {
+            CompressionMethod::None => Box::new(reader),
+            #[cfg(feature = "lzw")]
+            CompressionMethod::LZW => Box::new(super::stream::LZWReader::new(
+                reader,
+                usize::try_from(compressed_length)?,
+            )),
+            #[cfg(feature = "zstd")]
+            CompressionMethod::ZSTD => Box::new(zstd::Decoder::new(reader)?),
+            CompressionMethod::PackBits => Box::new(PackBitsReader::new(reader, compressed_length)),
+            #[cfg(feature = "deflate")]
+            CompressionMethod::Deflate | CompressionMethod::OldDeflate => {
+                Box::new(super::stream::DeflateReader::new(reader))
+            }
+            #[cfg(feature = "jpeg")]
+            CompressionMethod::ModernJPEG => {
+                use zune_jpeg::zune_core;
+
+                if jpeg_tables.is_some() && compressed_length < 2 {
+                    return Err(TiffError::FormatError(
+                        TiffFormatError::InvalidTagValueType(Tag::JPEGTables),
+                    ));
+                }
+
+                // Construct new jpeg_reader wrapping a SmartReader.
+                //
+                // JPEG compression in TIFF allows saving quantization and/or huffman tables in one
+                // central location. These `jpeg_tables` are simply prepended to the remaining jpeg image data.
+                // Because these `jpeg_tables` start with a `SOI` (HEX: `0xFFD8`) or __start of image__ marker
+                // which is also at the beginning of the remaining JPEG image data and would
+                // confuse the JPEG renderer, one of these has to be taken off. In this case the first two
+                // bytes of the remaining JPEG data is removed because it follows `jpeg_tables`.
+                // Similary, `jpeg_tables` ends with a `EOI` (HEX: `0xFFD9`) or __end of image__ marker,
+                // this has to be removed as well (last two bytes of `jpeg_tables`).
+                let mut jpeg_reader = match jpeg_tables {
+                    Some(jpeg_tables) => {
+                        let mut reader = reader.take(compressed_length);
+                        reader.read_exact(&mut [0; 2])?;
+
+                        Box::new(
+                            Cursor::new(&jpeg_tables[..jpeg_tables.len() - 2])
+                                .chain(reader.take(compressed_length)),
+                        ) as Box<dyn Read>
+                    }
+                    None => Box::new(reader.take(compressed_length)),
+                };
+
+                let mut jpeg_data = Vec::new();
+                jpeg_reader.read_to_end(&mut jpeg_data)?;
+
+                let mut decoder = zune_jpeg::JpegDecoder::new(jpeg_data);
+                let mut options: zune_core::options::DecoderOptions = Default::default();
+
+                // Disable color conversion by setting the output colorspace to the input
+                // colorspace.
+                decoder.decode_headers()?;
+                if let Some(colorspace) = decoder.get_input_colorspace() {
+                    options = options.jpeg_set_out_colorspace(colorspace);
+                }
+
+                decoder.set_options(options);
+
+                let data = decoder.decode()?;
+
+                Box::new(Cursor::new(data))
+            }
+            method => {
+                return Err(TiffError::UnsupportedError(
+                    TiffUnsupportedError::UnsupportedCompressionMethod(method),
+                ))
+            }
+        })
+    }
+
+    /// Samples per pixel within chunk.
+    ///
+    /// In planar config, samples are stored in separate strips/chunks, also called bands.
+    ///
+    /// Example with `bits_per_sample = [8, 8, 8]` and `PhotometricInterpretation::RGB`:
+    /// * `PlanarConfiguration::Chunky` -> 3 (RGBRGBRGB...)
+    /// * `PlanarConfiguration::Planar` -> 1 (RRR...) (GGG...) (BBB...)
+    pub(crate) fn samples_per_pixel(&self) -> usize {
+        match self.planar_config {
+            PlanarConfiguration::Chunky => self.samples.into(),
+            PlanarConfiguration::Planar => 1,
+        }
+    }
+
+    /// Number of strips per pixel.
+    pub(crate) fn strips_per_pixel(&self) -> usize {
+        match self.planar_config {
+            PlanarConfiguration::Chunky => 1,
+            PlanarConfiguration::Planar => self.samples.into(),
+        }
+    }
+
+    pub(crate) fn chunk_file_range(&self, chunk: u32) -> TiffResult<(u64, u64)> {
+        let file_offset = self
+            .chunk_offsets
+            .get(chunk as usize)
+            .ok_or(TiffError::FormatError(
+                TiffFormatError::InconsistentSizesEncountered,
+            ))?;
+
+        let compressed_bytes =
+            self.chunk_bytes
+                .get(chunk as usize)
+                .ok_or(TiffError::FormatError(
+                    TiffFormatError::InconsistentSizesEncountered,
+                ))?;
+
+        Ok((*file_offset, *compressed_bytes))
+    }
+
+    pub(crate) fn chunk_dimensions(&self) -> TiffResult<(u32, u32)> {
+        match self.chunk_type {
+            ChunkType::Strip => {
+                let strip_attrs = self.strip_decoder.as_ref().unwrap();
+                Ok((self.width, strip_attrs.rows_per_strip))
+            }
+            ChunkType::Tile => {
+                let tile_attrs = self.tile_attributes.as_ref().unwrap();
+                Ok((
+                    u32::try_from(tile_attrs.tile_width)?,
+                    u32::try_from(tile_attrs.tile_length)?,
+                ))
+            }
+        }
+    }
+
+    pub(crate) fn chunk_data_dimensions(&self, chunk_index: u32) -> TiffResult<(u32, u32)> {
+        let dims = self.chunk_dimensions()?;
+
+        match self.chunk_type {
+            ChunkType::Strip => {
+                let strip_attrs = self.strip_decoder.as_ref().unwrap();
+                let strips_per_band =
+                    self.height.saturating_sub(1) / strip_attrs.rows_per_strip + 1;
+                let strip_height_without_padding = (chunk_index % strips_per_band)
+                    .checked_mul(dims.1)
+                    .and_then(|x| self.height.checked_sub(x))
+                    .ok_or(TiffError::UsageError(UsageError::InvalidChunkIndex(
+                        chunk_index,
+                    )))?;
+
+                // Ignore potential vertical padding on the bottommost strip
+                let strip_height = dims.1.min(strip_height_without_padding);
+
+                Ok((dims.0, strip_height))
+            }
+            ChunkType::Tile => {
+                let tile_attrs = self.tile_attributes.as_ref().unwrap();
+                let (padding_right, padding_down) = tile_attrs.get_padding(chunk_index as usize);
+
+                let tile_width = tile_attrs.tile_width - padding_right;
+                let tile_length = tile_attrs.tile_length - padding_down;
+
+                Ok((u32::try_from(tile_width)?, u32::try_from(tile_length)?))
+            }
+        }
+    }
+
+    pub(crate) fn expand_chunk(
+        &self,
+        reader: &mut ValueReader<impl Read>,
+        buf: &mut [u8],
+        output_row_stride: usize,
+        chunk_index: u32,
+    ) -> TiffResult<()> {
+        let ValueReader {
+            reader,
+            bigtiff: _,
+            limits,
+        } = reader;
+
+        let byte_order = reader.byte_order;
+        let reader = reader.inner();
+
+        // Validate that the color type is supported.
+        let color_type = self.colortype()?;
+        match color_type {
+            ColorType::RGB(n)
+            | ColorType::RGBA(n)
+            | ColorType::CMYK(n)
+            | ColorType::CMYKA(n)
+            | ColorType::YCbCr(n)
+            | ColorType::Gray(n)
+            | ColorType::Multiband {
+                bit_depth: n,
+                num_samples: _,
+            } if n == 8 || n == 16 || n == 32 || n == 64 => {}
+            ColorType::Gray(n)
+            | ColorType::Multiband {
+                bit_depth: n,
+                num_samples: _,
+            } if n < 8 => match self.predictor {
+                Predictor::None => {}
+                Predictor::Horizontal => {
+                    return Err(TiffError::UnsupportedError(
+                        TiffUnsupportedError::HorizontalPredictor(color_type),
+                    ));
+                }
+                Predictor::FloatingPoint => {
+                    return Err(TiffError::UnsupportedError(
+                        TiffUnsupportedError::FloatingPointPredictor(color_type),
+                    ));
+                }
+            },
+            type_ => {
+                return Err(TiffError::UnsupportedError(
+                    TiffUnsupportedError::UnsupportedColorType(type_),
+                ));
+            }
+        }
+
+        // Validate that the predictor is supported for the sample type.
+        match (self.predictor, self.sample_format) {
+            (
+                Predictor::Horizontal,
+                SampleFormat::Int | SampleFormat::Uint | SampleFormat::IEEEFP,
+            ) => {}
+            (Predictor::Horizontal, _) => {
+                return Err(TiffError::UnsupportedError(
+                    TiffUnsupportedError::HorizontalPredictor(color_type),
+                ));
+            }
+            (Predictor::FloatingPoint, SampleFormat::IEEEFP) => {}
+            (Predictor::FloatingPoint, _) => {
+                return Err(TiffError::UnsupportedError(
+                    TiffUnsupportedError::FloatingPointPredictor(color_type),
+                ));
+            }
+            _ => {}
+        }
+
+        let compressed_bytes =
+            self.chunk_bytes
+                .get(chunk_index as usize)
+                .ok_or(TiffError::FormatError(
+                    TiffFormatError::InconsistentSizesEncountered,
+                ))?;
+        if *compressed_bytes > limits.intermediate_buffer_size as u64 {
+            return Err(TiffError::LimitsExceeded);
+        }
+
+        let compression_method = self.compression_method;
+        let photometric_interpretation = self.photometric_interpretation;
+        let predictor = self.predictor;
+        let samples = self.samples_per_pixel();
+
+        let chunk_dims = self.chunk_dimensions()?;
+        let data_dims = self.chunk_data_dimensions(chunk_index)?;
+
+        let chunk_row_bits = (u64::from(chunk_dims.0) * u64::from(self.bits_per_sample))
+            .checked_mul(samples as u64)
+            .ok_or(TiffError::LimitsExceeded)?;
+        let chunk_row_bytes: usize = ((chunk_row_bits + 7) / 8).try_into()?;
+
+        let data_row_bits = (u64::from(data_dims.0) * u64::from(self.bits_per_sample))
+            .checked_mul(samples as u64)
+            .ok_or(TiffError::LimitsExceeded)?;
+        let data_row_bytes: usize = ((data_row_bits + 7) / 8).try_into()?;
+
+        // TODO: Should these return errors instead?
+        assert!(output_row_stride >= data_row_bytes);
+        assert!(buf.len() >= output_row_stride * (data_dims.1 as usize - 1) + data_row_bytes);
+
+        let mut reader = Self::create_reader(
+            reader,
+            compression_method,
+            *compressed_bytes,
+            self.jpeg_tables.as_deref().map(|a| &**a),
+        )?;
+
+        if output_row_stride == chunk_row_bytes as usize {
+            let tile = &mut buf[..chunk_row_bytes * data_dims.1 as usize];
+            reader.read_exact(tile)?;
+
+            for row in tile.chunks_mut(chunk_row_bytes as usize) {
+                super::fix_endianness_and_predict(
+                    row,
+                    color_type.bit_depth(),
+                    samples,
+                    byte_order,
+                    predictor,
+                );
+            }
+            if photometric_interpretation == PhotometricInterpretation::WhiteIsZero {
+                super::invert_colors(tile, color_type, self.sample_format);
+            }
+        } else if chunk_row_bytes > data_row_bytes && self.predictor == Predictor::FloatingPoint {
+            // The floating point predictor shuffles the padding bytes into the encoded output, so
+            // this case is handled specially when needed.
+            let mut encoded = vec![0u8; chunk_row_bytes];
+            for row in buf.chunks_mut(output_row_stride).take(data_dims.1 as usize) {
+                reader.read_exact(&mut encoded)?;
+
+                let row = &mut row[..data_row_bytes];
+                match color_type.bit_depth() {
+                    16 => predict_f16(&mut encoded, row, samples),
+                    32 => predict_f32(&mut encoded, row, samples),
+                    64 => predict_f64(&mut encoded, row, samples),
+                    _ => unreachable!(),
+                }
+                if photometric_interpretation == PhotometricInterpretation::WhiteIsZero {
+                    super::invert_colors(row, color_type, self.sample_format);
+                }
+            }
+        } else {
+            for (_i, row) in buf
+                .chunks_mut(output_row_stride)
+                .take(data_dims.1 as usize)
+                .enumerate()
+            {
+                let row = &mut row[..data_row_bytes];
+                reader.read_exact(row)?;
+
+                // Skip horizontal padding
+                if chunk_row_bytes > data_row_bytes {
+                    let len = u64::try_from(chunk_row_bytes - data_row_bytes)?;
+                    io::copy(&mut reader.by_ref().take(len), &mut io::sink())?;
+                }
+
+                super::fix_endianness_and_predict(
+                    row,
+                    color_type.bit_depth(),
+                    samples,
+                    byte_order,
+                    predictor,
+                );
+                if photometric_interpretation == PhotometricInterpretation::WhiteIsZero {
+                    super::invert_colors(row, color_type, self.sample_format);
+                }
+            }
+        }
+
+        Ok(())
+    }
+}

src/decoder/stream.rs

@@ -1,10 +1,6 @@
 //! All IO functionality needed for TIFF decoding
 
-use crate::error::{TiffError, TiffResult};
-use byteorder::{BigEndian, LittleEndian, ReadBytesExt};
-use lzw;
-use miniz_oxide::inflate;
-use std::io::{self, Read, Seek};
+use std::io::{self, BufRead, BufReader, Read, Seek, Take};
 
 /// Byte order of the TIFF file.
 #[derive(Clone, Copy, Debug)]
@@ -16,271 +12,269 @@ pub enum ByteOrder {
 }
 
 /// Reader that is aware of the byte order.
-pub trait EndianReader: Read {
-    /// Byte order that should be adhered to
-    fn byte_order(&self) -> ByteOrder;
+#[derive(Debug)]
+pub struct EndianReader<R> {
+    reader: R,
+    pub(crate) byte_order: ByteOrder,
+}
+
+impl<R: Read> EndianReader<R> {
+    pub fn new(reader: R, byte_order: ByteOrder) -> Self {
+        Self { reader, byte_order }
+    }
+
+    pub fn inner(&mut self) -> &mut R {
+        &mut self.reader
+    }
+
+    pub fn goto_offset(&mut self, offset: u64) -> io::Result<()>
+    where
+        R: Seek,
+    {
+        self.reader.seek(io::SeekFrom::Start(offset))?;
+        Ok(())
+    }
 
     /// Reads an u16
     #[inline(always)]
-    fn read_u16(&mut self) -> Result<u16, io::Error> {
-        match self.byte_order() {
-            ByteOrder::LittleEndian => <Self as ReadBytesExt>::read_u16::<LittleEndian>(self),
-            ByteOrder::BigEndian => <Self as ReadBytesExt>::read_u16::<BigEndian>(self),
-        }
+    pub fn read_u16(&mut self) -> Result<u16, io::Error> {
+        let mut n = [0u8; 2];
+        self.reader.read_exact(&mut n)?;
+        Ok(match self.byte_order {
+            ByteOrder::LittleEndian => u16::from_le_bytes(n),
+            ByteOrder::BigEndian => u16::from_be_bytes(n),
+        })
     }
 
+    /// Reads an i8
     #[inline(always)]
-    fn read_u16_into(&mut self, buffer: &mut [u16]) -> Result<(), io::Error> {
-        match self.byte_order() {
-            ByteOrder::LittleEndian => {
-                <Self as ReadBytesExt>::read_u16_into::<LittleEndian>(self, buffer)
-            }
-            ByteOrder::BigEndian => {
-                <Self as ReadBytesExt>::read_u16_into::<BigEndian>(self, buffer)
-            }
-        }
+    pub fn read_i8(&mut self) -> Result<i8, io::Error> {
+        let mut n = [0u8; 1];
+        self.reader.read_exact(&mut n)?;
+        Ok(match self.byte_order {
+            ByteOrder::LittleEndian => i8::from_le_bytes(n),
+            ByteOrder::BigEndian => i8::from_be_bytes(n),
+        })
     }
 
     /// Reads an i16
     #[inline(always)]
-    fn read_i16(&mut self) -> Result<i16, io::Error> {
-        match self.byte_order() {
-            ByteOrder::LittleEndian => <Self as ReadBytesExt>::read_i16::<LittleEndian>(self),
-            ByteOrder::BigEndian => <Self as ReadBytesExt>::read_i16::<BigEndian>(self),
-        }
+    pub fn read_i16(&mut self) -> Result<i16, io::Error> {
+        let mut n = [0u8; 2];
+        self.reader.read_exact(&mut n)?;
+        Ok(match self.byte_order {
+            ByteOrder::LittleEndian => i16::from_le_bytes(n),
+            ByteOrder::BigEndian => i16::from_be_bytes(n),
+        })
     }
 
     /// Reads an u32
     #[inline(always)]
-    fn read_u32(&mut self) -> Result<u32, io::Error> {
-        match self.byte_order() {
-            ByteOrder::LittleEndian => <Self as ReadBytesExt>::read_u32::<LittleEndian>(self),
-            ByteOrder::BigEndian => <Self as ReadBytesExt>::read_u32::<BigEndian>(self),
-        }
+    pub fn read_u32(&mut self) -> Result<u32, io::Error> {
+        let mut n = [0u8; 4];
+        self.reader.read_exact(&mut n)?;
+        Ok(match self.byte_order {
+            ByteOrder::LittleEndian => u32::from_le_bytes(n),
+            ByteOrder::BigEndian => u32::from_be_bytes(n),
+        })
     }
 
     /// Reads an i32
     #[inline(always)]
-    fn read_i32(&mut self) -> Result<i32, io::Error> {
-        match self.byte_order() {
-            ByteOrder::LittleEndian => <Self as ReadBytesExt>::read_i32::<LittleEndian>(self),
-            ByteOrder::BigEndian => <Self as ReadBytesExt>::read_i32::<BigEndian>(self),
-        }
+    pub fn read_i32(&mut self) -> Result<i32, io::Error> {
+        let mut n = [0u8; 4];
+        self.reader.read_exact(&mut n)?;
+        Ok(match self.byte_order {
+            ByteOrder::LittleEndian => i32::from_le_bytes(n),
+            ByteOrder::BigEndian => i32::from_be_bytes(n),
+        })
+    }
+
+    /// Reads an u64
+    #[inline(always)]
+    pub fn read_u64(&mut self) -> Result<u64, io::Error> {
+        let mut n = [0u8; 8];
+        self.reader.read_exact(&mut n)?;
+        Ok(match self.byte_order {
+            ByteOrder::LittleEndian => u64::from_le_bytes(n),
+            ByteOrder::BigEndian => u64::from_be_bytes(n),
+        })
+    }
+
+    /// Reads an i64
+    #[inline(always)]
+    pub fn read_i64(&mut self) -> Result<i64, io::Error> {
+        let mut n = [0u8; 8];
+        self.reader.read_exact(&mut n)?;
+        Ok(match self.byte_order {
+            ByteOrder::LittleEndian => i64::from_le_bytes(n),
+            ByteOrder::BigEndian => i64::from_be_bytes(n),
+        })
+    }
+
+    /// Reads an f32
+    #[inline(always)]
+    pub fn read_f32(&mut self) -> Result<f32, io::Error> {
+        let mut n = [0u8; 4];
+        self.reader.read_exact(&mut n)?;
+        Ok(f32::from_bits(match self.byte_order {
+            ByteOrder::LittleEndian => u32::from_le_bytes(n),
+            ByteOrder::BigEndian => u32::from_be_bytes(n),
+        }))
+    }
+
+    /// Reads an f64
+    #[inline(always)]
+    pub fn read_f64(&mut self) -> Result<f64, io::Error> {
+        let mut n = [0u8; 8];
+        self.reader.read_exact(&mut n)?;
+        Ok(f64::from_bits(match self.byte_order {
+            ByteOrder::LittleEndian => u64::from_le_bytes(n),
+            ByteOrder::BigEndian => u64::from_be_bytes(n),
+        }))
     }
 }
 
-/// Reader that decompresses DEFLATE streams
-pub struct DeflateReader {
-    buffer: io::Cursor<Vec<u8>>,
-    byte_order: ByteOrder,
-}
+///
+/// # READERS
+///
 
-impl DeflateReader {
-    pub fn new<R: Read + Seek>(
-        reader: &mut SmartReader<R>,
-        max_uncompressed_length: usize,
-    ) -> TiffResult<(usize, Self)> {
-        let byte_order = reader.byte_order;
-        let mut compressed = Vec::new();
-        reader.read_to_end(&mut compressed)?;
+///
+/// ## Deflate Reader
+///
 
-        // TODO: Implement streaming compression, and remove this (temporary) and somewhat
-        // misleading workaround.
-        if compressed.len() > max_uncompressed_length {
-            return Err(TiffError::LimitsExceeded);
-        }
+#[cfg(feature = "deflate")]
+pub type DeflateReader<R> = flate2::read::ZlibDecoder<R>;
 
-        let uncompressed =
-            inflate::decompress_to_vec_zlib(&compressed).map_err(TiffError::from_inflate_status)?;
-
-        Ok((
-            uncompressed.len(),
-            Self {
-                byte_order,
-                buffer: io::Cursor::new(uncompressed),
-            },
-        ))
-    }
-}
-
-impl Read for DeflateReader {
-    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
-        self.buffer.read(buf)
-    }
-}
-
-impl EndianReader for DeflateReader {
-    fn byte_order(&self) -> ByteOrder {
-        self.byte_order
-    }
-}
+///
+/// ## LZW Reader
+///
 
 /// Reader that decompresses LZW streams
-pub struct LZWReader {
-    buffer: io::Cursor<Vec<u8>>,
-    byte_order: ByteOrder,
+#[cfg(feature = "lzw")]
+pub struct LZWReader<R: Read> {
+    reader: BufReader<Take<R>>,
+    decoder: weezl::decode::Decoder,
 }
 
-impl LZWReader {
+#[cfg(feature = "lzw")]
+impl<R: Read> LZWReader<R> {
     /// Wraps a reader
-    pub fn new<R>(
-        reader: &mut SmartReader<R>,
-        compressed_length: usize,
-        max_uncompressed_length: usize,
-    ) -> io::Result<(usize, LZWReader)>
-    where
-        R: Read + Seek,
-    {
-        let order = reader.byte_order;
-        let mut compressed = vec![0; compressed_length as usize];
-        reader.read_exact(&mut compressed[..])?;
-        let mut uncompressed = Vec::with_capacity(max_uncompressed_length);
-        let mut decoder = lzw::DecoderEarlyChange::new(lzw::MsbReader::new(), 8);
-        let mut bytes_read = 0;
-        while bytes_read < compressed_length && uncompressed.len() < max_uncompressed_length {
-            let (len, bytes) = decoder.decode_bytes(&compressed[bytes_read..])?;
-            bytes_read += len;
-            uncompressed.extend_from_slice(bytes);
+    pub fn new(reader: R, compressed_length: usize) -> LZWReader<R> {
+        let configuration =
+            weezl::decode::Configuration::with_tiff_size_switch(weezl::BitOrder::Msb, 8)
+                .with_yield_on_full_buffer(true);
+        Self {
+            reader: BufReader::with_capacity(
+                (32 * 1024).min(compressed_length),
+                reader.take(u64::try_from(compressed_length).unwrap()),
+            ),
+            decoder: configuration.build(),
         }
-
-        let bytes = uncompressed.len();
-        Ok((
-            bytes,
-            LZWReader {
-                buffer: io::Cursor::new(uncompressed),
-                byte_order: order,
-            },
-        ))
     }
 }
 
-impl Read for LZWReader {
-    #[inline]
+#[cfg(feature = "lzw")]
+impl<R: Read> Read for LZWReader<R> {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
-        self.buffer.read(buf)
+        loop {
+            let result = self.decoder.decode_bytes(self.reader.fill_buf()?, buf);
+            self.reader.consume(result.consumed_in);
+
+            match result.status {
+                Ok(weezl::LzwStatus::Ok) => {
+                    if result.consumed_out == 0 {
+                        continue;
+                    } else {
+                        return Ok(result.consumed_out);
+                    }
+                }
+                Ok(weezl::LzwStatus::NoProgress) => {
+                    assert_eq!(result.consumed_in, 0);
+                    assert_eq!(result.consumed_out, 0);
+                    assert!(self.reader.buffer().is_empty());
+                    return Err(io::Error::new(
+                        io::ErrorKind::UnexpectedEof,
+                        "no lzw end code found",
+                    ));
+                }
+                Ok(weezl::LzwStatus::Done) => {
+                    return Ok(result.consumed_out);
+                }
+                Err(err) => return Err(io::Error::new(io::ErrorKind::InvalidData, err)),
+            }
+        }
     }
 }
 
-impl EndianReader for LZWReader {
-    #[inline(always)]
-    fn byte_order(&self) -> ByteOrder {
-        self.byte_order
-    }
+///
+/// ## PackBits Reader
+///
+
+enum PackBitsReaderState {
+    Header,
+    Literal,
+    Repeat { value: u8 },
 }
 
 /// Reader that unpacks Apple's `PackBits` format
-pub struct PackBitsReader {
-    buffer: io::Cursor<Vec<u8>>,
-    byte_order: ByteOrder,
+pub struct PackBitsReader<R: Read> {
+    reader: Take<R>,
+    state: PackBitsReaderState,
+    count: usize,
 }
 
-impl PackBitsReader {
+impl<R: Read> PackBitsReader<R> {
     /// Wraps a reader
-    pub fn new<R: Read + Seek>(
-        mut reader: R,
-        byte_order: ByteOrder,
-        length: usize,
-    ) -> io::Result<(usize, PackBitsReader)> {
-        let mut buffer = Vec::new();
-        let mut read: usize = 0;
-        while read < length {
-            let lread = read_packbits_run(&mut reader, &mut buffer)?;
-            if lread == 0 {
-                return Err(io::ErrorKind::UnexpectedEof.into());
-            }
-            read += lread;
+    pub fn new(reader: R, length: u64) -> Self {
+        Self {
+            reader: reader.take(length),
+            state: PackBitsReaderState::Header,
+            count: 0,
         }
-        Ok((
-            buffer.len(),
-            PackBitsReader {
-                buffer: io::Cursor::new(buffer),
-                byte_order,
-            },
-        ))
     }
 }
 
-fn read_packbits_run<R: Read + Seek>(reader: &mut R, buffer: &mut Vec<u8>) -> io::Result<usize> {
-    let mut header: [u8; 1] = [0];
-
-    let bytes = reader.read(&mut header)?;
-
-    match bytes {
-        0 => Ok(0),
-        _ => match header[0] as i8 {
-            -128 => Ok(1),
-            h if h >= -127 && h <= -1 => {
-                let new_len = buffer.len() + (1 - h as isize) as usize;
-                reader.read_exact(&mut header)?;
-                buffer.resize(new_len, header[0]);
-                Ok(2)
-            }
-            h => {
-                let num_vals = h as usize + 1;
-                let start = buffer.len();
-                buffer.resize(start + num_vals, 0);
-                reader.read_exact(&mut buffer[start..])?;
-                Ok(num_vals + 1)
-            }
-        },
-    }
-}
-
-impl Read for PackBitsReader {
-    #[inline]
+impl<R: Read> Read for PackBitsReader<R> {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
-        self.buffer.read(buf)
-    }
-}
+        while let PackBitsReaderState::Header = self.state {
+            if self.reader.limit() == 0 {
+                return Ok(0);
+            }
+            let mut header: [u8; 1] = [0];
+            self.reader.read_exact(&mut header)?;
+            let h = header[0] as i8;
+            if (-127..=-1).contains(&h) {
+                let mut data: [u8; 1] = [0];
+                self.reader.read_exact(&mut data)?;
+                self.state = PackBitsReaderState::Repeat { value: data[0] };
+                self.count = (1 - h as isize) as usize;
+            } else if h >= 0 {
+                self.state = PackBitsReaderState::Literal;
+                self.count = h as usize + 1;
+            } else {
+                // h = -128 is a no-op.
+            }
+        }
 
-impl EndianReader for PackBitsReader {
-    #[inline(always)]
-    fn byte_order(&self) -> ByteOrder {
-        self.byte_order
-    }
-}
+        let length = buf.len().min(self.count);
+        let actual = match self.state {
+            PackBitsReaderState::Literal => self.reader.read(&mut buf[..length])?,
+            PackBitsReaderState::Repeat { value } => {
+                for b in &mut buf[..length] {
+                    *b = value;
+                }
 
-/// Reader that is aware of the byte order.
-#[derive(Debug)]
-pub struct SmartReader<R>
-where
-    R: Read + Seek,
-{
-    reader: R,
-    pub byte_order: ByteOrder,
-}
+                length
+            }
+            PackBitsReaderState::Header => unreachable!(),
+        };
 
-impl<R> SmartReader<R>
-where
-    R: Read + Seek,
-{
-    /// Wraps a reader
-    pub fn wrap(reader: R, byte_order: ByteOrder) -> SmartReader<R> {
-        SmartReader { reader, byte_order }
-    }
-}
-
-impl<R> EndianReader for SmartReader<R>
-where
-    R: Read + Seek,
-{
-    #[inline(always)]
-    fn byte_order(&self) -> ByteOrder {
-        self.byte_order
-    }
-}
-
-impl<R: Read + Seek> Read for SmartReader<R> {
-    #[inline]
-    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
-        self.reader.read(buf)
-    }
-}
-
-impl<R: Read + Seek> Seek for SmartReader<R> {
-    #[inline]
-    fn seek(&mut self, pos: io::SeekFrom) -> io::Result<u64> {
-        self.reader.seek(pos)
+        self.count -= actual;
+        if self.count == 0 {
+            self.state = PackBitsReaderState::Header;
+        }
+        Ok(actual)
     }
 }
 
@@ -297,8 +291,7 @@ mod test {
         let encoded_len = encoded.len();
 
         let buff = io::Cursor::new(encoded);
-        let (_, mut decoder) =
-            PackBitsReader::new(buff, ByteOrder::LittleEndian, encoded_len).unwrap();
+        let mut decoder = PackBitsReader::new(buff, encoded_len as u64);
 
         let mut decoded = Vec::new();
         decoder.read_to_end(&mut decoded).unwrap();

src/decoder/tag_reader.rs

@@ -0,0 +1,57 @@
+use std::io::{Read, Seek};
+
+use crate::{tags::Tag, Directory};
+use crate::{TiffError, TiffFormatError, TiffResult};
+
+use super::ifd::{Entry, Value};
+use super::ValueReader;
+
+pub(crate) struct TagReader<'lt, R: EntryDecoder + ?Sized> {
+    pub(crate) decoder: &'lt mut R,
+    pub(crate) ifd: &'lt Directory,
+}
+
+pub(crate) trait EntryDecoder {
+    /// Turn an entry into a value by fetching the required bytes in the stream.
+    fn entry_val(&mut self, entry: &Entry) -> TiffResult<Value>;
+}
+
+impl<R: Seek + Read> EntryDecoder for ValueReader<R> {
+    fn entry_val(&mut self, entry: &Entry) -> TiffResult<Value> {
+        entry.val(&self.limits, self.bigtiff, &mut self.reader)
+    }
+}
+
+impl<'a, R: EntryDecoder + ?Sized> TagReader<'a, R> {
+    pub(crate) fn find_tag(&mut self, tag: Tag) -> TiffResult<Option<Value>> {
+        let entry = match self.ifd.get(tag) {
+            None => return Ok(None),
+            Some(entry) => entry.clone(),
+        };
+
+        self.decoder.entry_val(&entry).map(Some)
+    }
+
+    pub(crate) fn require_tag(&mut self, tag: Tag) -> TiffResult<Value> {
+        match self.find_tag(tag)? {
+            Some(val) => Ok(val),
+            None => Err(TiffError::FormatError(
+                TiffFormatError::RequiredTagNotFound(tag),
+            )),
+        }
+    }
+
+    pub fn find_tag_uint_vec<T: TryFrom<u64>>(&mut self, tag: Tag) -> TiffResult<Option<Vec<T>>> {
+        self.find_tag(tag)?
+            .map(|v| v.into_u64_vec())
+            .transpose()?
+            .map(|v| {
+                v.into_iter()
+                    .map(|u| {
+                        T::try_from(u).map_err(|_| TiffFormatError::InvalidTagValueType(tag).into())
+                    })
+                    .collect()
+            })
+            .transpose()
+    }
+}

src/directory.rs

@@ -0,0 +1,158 @@
+use core::fmt;
+use std::{collections::BTreeMap, num::NonZeroU64};
+
+use crate::{
+    decoder::ifd::Entry,
+    tags::{IfdPointer, Tag},
+};
+
+/// An Image File Directory (IFD).
+///
+/// A directory is a map of [`Tag`]s to [`Value`](crate::decoder::ifd::Value)s. The values are
+/// stored anywhere in the file, with the directory containing the offsets and length of the
+/// associated values for each tag present in the directory.
+///
+/// A directory can be created with with
+/// [`Decoder::read_directory`](crate::decoder::Decoder::read_directory) or as an empty directory
+/// to be extended with entries. A directory may be used with
+/// [`Decoder::read_directory_tags`](crate::decoder::Decoder::read_directory_tags) to read the
+/// values associated with tags from an underlying file.
+#[doc(alias = "IFD")]
+pub struct Directory {
+    /// There are at most `u16::MAX` entries in any single directory, the count is stored as a
+    /// 2-byte value. The order in the file is implied to be ascending by tag value (the decoder
+    /// does not mind unordered entries).
+    pub(crate) entries: BTreeMap<u16, Entry>,
+    pub(crate) next_ifd: Option<NonZeroU64>,
+}
+
+impl Directory {
+    pub fn empty() -> Self {
+        Directory {
+            entries: BTreeMap::new(),
+            next_ifd: None,
+        }
+    }
+
+    /// Retrieve the value associated with a tag.
+    pub fn get(&self, tag: Tag) -> Option<&Entry> {
+        self.entries.get(&tag.to_u16())
+    }
+
+    /// Check if the directory contains a specified tag.
+    pub fn contains(&self, tag: Tag) -> bool {
+        self.entries.contains_key(&tag.to_u16())
+    }
+
+    /// Iterate over all known and unknown tags in this directory.
+    pub fn iter(&self) -> impl Iterator<Item = (Tag, &Entry)> + '_ {
+        self.entries
+            .iter()
+            .map(|(k, v)| (Tag::from_u16_exhaustive(*k), v))
+    }
+
+    /// Insert additional entries into the directory.
+    ///
+    /// Note that a directory can contain at most `u16::MAX` values. There may be one entry that
+    /// does not fit into the directory. This entry is silently ignored (please check [`Self::len`]
+    /// to detect the condition). Providing a tag multiple times or a tag that already exists
+    /// within this directory overwrites the entry.
+    pub fn extend(&mut self, iter: impl IntoIterator<Item = (Tag, Entry)>) {
+        // Code size conscious extension, avoid monomorphic extensions with the assumption of these
+        // not being performance sensitive in practice. (Maybe we have a polymorphic interface for
+        // the crate usage in the future.
+        self.extend_inner(iter.into_iter().by_ref())
+    }
+
+    /// Get the number of entries.
+    pub fn len(&self) -> usize {
+        // The keys are `u16`. Since IFDs are required to have at least one entry this would have
+        // been a trivial thing to do in the specification by storing it minus one but alas. In
+        // BigTIFF the count is stored as 8-bit anyways.
+        self.entries.len()
+    }
+
+    /// Get the pointer to the next IFD, if it was defined.
+    pub fn next(&self) -> Option<IfdPointer> {
+        self.next_ifd.map(|n| IfdPointer(n.get()))
+    }
+
+    pub fn set_next(&mut self, next: Option<IfdPointer>) {
+        self.next_ifd = next.and_then(|n| NonZeroU64::new(n.0));
+    }
+
+    fn extend_inner(&mut self, iter: &mut dyn Iterator<Item = (Tag, Entry)>) {
+        for (tag, entry) in iter {
+            // If the tag is already present, it will be overwritten.
+            let map_entry = self.entries.entry(tag.to_u16());
+
+            match map_entry {
+                std::collections::btree_map::Entry::Vacant(vacant_entry) => {
+                    vacant_entry.insert(entry);
+                }
+                std::collections::btree_map::Entry::Occupied(mut occupied_entry) => {
+                    occupied_entry.insert(entry);
+                }
+            }
+        }
+    }
+}
+
+impl fmt::Debug for Directory {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("Directory")
+            .field(
+                "entries",
+                &self.entries.iter().map(|(k, v)| (Tag::from_u16(*k), v)),
+            )
+            .field("next_ifd", &self.next_ifd)
+            .finish()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Directory;
+    use crate::{decoder::ifd::Entry, tags::Tag};
+
+    #[test]
+    fn directory_multiple_entries() {
+        let mut dir = Directory::empty();
+        assert_eq!(dir.len(), 0);
+
+        dir.extend((0..=u16::MAX).map(|i| {
+            let tag = Tag::Unknown(1);
+            let entry = Entry::new_u64(crate::tags::Type::BYTE, i.into(), [0; 8]);
+            (tag, entry)
+        }));
+
+        assert_eq!(dir.len(), 1, "Only one tag was ever modified");
+
+        assert_eq!(
+            dir.get(Tag::Unknown(1))
+                .expect("tag 1 should be present after this chain")
+                .count(),
+            u16::MAX.into()
+        );
+    }
+
+    #[test]
+    fn iteration_order() {
+        let mut dir = Directory::empty();
+        assert_eq!(dir.len(), 0);
+
+        let fake_entry = Entry::new_u64(crate::tags::Type::BYTE, 0, [0; 8]);
+        dir.extend((0..32).map(|i| {
+            let tag = Tag::Unknown(i);
+            let entry = fake_entry.clone();
+            (tag, entry)
+        }));
+
+        let iter_order: Vec<u16> = dir.iter().map(|(tag, _e)| tag.to_u16()).collect();
+        assert_eq!(
+            iter_order,
+            (0..32).collect::<Vec<_>>(),
+            "Tags must be in ascending order according to the specification"
+        );
+    }
+}

src/encoder/colortype.rs

@@ -1,4 +1,30 @@
-use decoder::PhotometricInterpretation;
+use crate::tags::{PhotometricInterpretation, SampleFormat};
+
+macro_rules! integer_horizontal_predict {
+    () => {
+        fn horizontal_predict(row: &[Self::Inner], result: &mut Vec<Self::Inner>) {
+            let sample_size = Self::SAMPLE_FORMAT.len();
+
+            if row.len() < sample_size {
+                debug_assert!(false);
+                return;
+            }
+
+            let (start, rest) = row.split_at(sample_size);
+
+            result.extend_from_slice(start);
+            if result.capacity() - result.len() < rest.len() {
+                return;
+            }
+
+            result.extend(
+                row.into_iter()
+                    .zip(rest)
+                    .map(|(prev, current)| current.wrapping_sub(*prev)),
+            );
+        }
+    };
+}
 
 /// Trait for different colortypes that can be encoded.
 pub trait ColorType {
@@ -8,6 +34,10 @@ pub trait ColorType {
     const TIFF_VALUE: PhotometricInterpretation;
     /// The value of the tiff tag `BitsPerSample`
     const BITS_PER_SAMPLE: &'static [u16];
+    /// The value of the tiff tag `SampleFormat`
+    const SAMPLE_FORMAT: &'static [SampleFormat];
+
+    fn horizontal_predict(row: &[Self::Inner], result: &mut Vec<Self::Inner>);
 }
 
 pub struct Gray8;
@@ -15,6 +45,19 @@ impl ColorType for Gray8 {
     type Inner = u8;
     const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::BlackIsZero;
     const BITS_PER_SAMPLE: &'static [u16] = &[8];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Uint];
+
+    integer_horizontal_predict!();
+}
+
+pub struct GrayI8;
+impl ColorType for GrayI8 {
+    type Inner = i8;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::BlackIsZero;
+    const BITS_PER_SAMPLE: &'static [u16] = &[8];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Int];
+
+    integer_horizontal_predict!();
 }
 
 pub struct Gray16;
@@ -22,6 +65,83 @@ impl ColorType for Gray16 {
     type Inner = u16;
     const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::BlackIsZero;
     const BITS_PER_SAMPLE: &'static [u16] = &[16];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Uint];
+
+    integer_horizontal_predict!();
+}
+
+pub struct GrayI16;
+impl ColorType for GrayI16 {
+    type Inner = i16;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::BlackIsZero;
+    const BITS_PER_SAMPLE: &'static [u16] = &[16];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Int];
+
+    integer_horizontal_predict!();
+}
+
+pub struct Gray32;
+impl ColorType for Gray32 {
+    type Inner = u32;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::BlackIsZero;
+    const BITS_PER_SAMPLE: &'static [u16] = &[32];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Uint];
+
+    integer_horizontal_predict!();
+}
+
+pub struct GrayI32;
+impl ColorType for GrayI32 {
+    type Inner = i32;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::BlackIsZero;
+    const BITS_PER_SAMPLE: &'static [u16] = &[32];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Int];
+
+    integer_horizontal_predict!();
+}
+
+pub struct Gray32Float;
+impl ColorType for Gray32Float {
+    type Inner = f32;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::BlackIsZero;
+    const BITS_PER_SAMPLE: &'static [u16] = &[32];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::IEEEFP];
+
+    fn horizontal_predict(_: &[Self::Inner], _: &mut Vec<Self::Inner>) {
+        unreachable!()
+    }
+}
+
+pub struct Gray64;
+impl ColorType for Gray64 {
+    type Inner = u64;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::BlackIsZero;
+    const BITS_PER_SAMPLE: &'static [u16] = &[64];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Uint];
+
+    integer_horizontal_predict!();
+}
+
+pub struct GrayI64;
+impl ColorType for GrayI64 {
+    type Inner = i64;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::BlackIsZero;
+    const BITS_PER_SAMPLE: &'static [u16] = &[64];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Int];
+
+    integer_horizontal_predict!();
+}
+
+pub struct Gray64Float;
+impl ColorType for Gray64Float {
+    type Inner = f64;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::BlackIsZero;
+    const BITS_PER_SAMPLE: &'static [u16] = &[64];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::IEEEFP];
+
+    fn horizontal_predict(_: &[Self::Inner], _: &mut Vec<Self::Inner>) {
+        unreachable!()
+    }
 }
 
 pub struct RGB8;
@@ -29,6 +149,9 @@ impl ColorType for RGB8 {
     type Inner = u8;
     const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::RGB;
     const BITS_PER_SAMPLE: &'static [u16] = &[8, 8, 8];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Uint; 3];
+
+    integer_horizontal_predict!();
 }
 
 pub struct RGB16;
@@ -36,6 +159,51 @@ impl ColorType for RGB16 {
     type Inner = u16;
     const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::RGB;
     const BITS_PER_SAMPLE: &'static [u16] = &[16, 16, 16];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Uint; 3];
+
+    integer_horizontal_predict!();
+}
+
+pub struct RGB32;
+impl ColorType for RGB32 {
+    type Inner = u32;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::RGB;
+    const BITS_PER_SAMPLE: &'static [u16] = &[32, 32, 32];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Uint; 3];
+
+    integer_horizontal_predict!();
+}
+
+pub struct RGB32Float;
+impl ColorType for RGB32Float {
+    type Inner = f32;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::RGB;
+    const BITS_PER_SAMPLE: &'static [u16] = &[32, 32, 32];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::IEEEFP; 3];
+    fn horizontal_predict(_: &[Self::Inner], _: &mut Vec<Self::Inner>) {
+        unreachable!()
+    }
+}
+
+pub struct RGB64;
+impl ColorType for RGB64 {
+    type Inner = u64;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::RGB;
+    const BITS_PER_SAMPLE: &'static [u16] = &[64, 64, 64];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Uint; 3];
+
+    integer_horizontal_predict!();
+}
+
+pub struct RGB64Float;
+impl ColorType for RGB64Float {
+    type Inner = f64;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::RGB;
+    const BITS_PER_SAMPLE: &'static [u16] = &[64, 64, 64];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::IEEEFP; 3];
+    fn horizontal_predict(_: &[Self::Inner], _: &mut Vec<Self::Inner>) {
+        unreachable!()
+    }
 }
 
 pub struct RGBA8;
@@ -43,6 +211,9 @@ impl ColorType for RGBA8 {
     type Inner = u8;
     const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::RGB;
     const BITS_PER_SAMPLE: &'static [u16] = &[8, 8, 8, 8];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Uint; 4];
+
+    integer_horizontal_predict!();
 }
 
 pub struct RGBA16;
@@ -50,6 +221,51 @@ impl ColorType for RGBA16 {
     type Inner = u16;
     const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::RGB;
     const BITS_PER_SAMPLE: &'static [u16] = &[16, 16, 16, 16];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Uint; 4];
+
+    integer_horizontal_predict!();
+}
+
+pub struct RGBA32;
+impl ColorType for RGBA32 {
+    type Inner = u32;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::RGB;
+    const BITS_PER_SAMPLE: &'static [u16] = &[32, 32, 32, 32];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Uint; 4];
+
+    integer_horizontal_predict!();
+}
+
+pub struct RGBA32Float;
+impl ColorType for RGBA32Float {
+    type Inner = f32;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::RGB;
+    const BITS_PER_SAMPLE: &'static [u16] = &[32, 32, 32, 32];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::IEEEFP; 4];
+    fn horizontal_predict(_: &[Self::Inner], _: &mut Vec<Self::Inner>) {
+        unreachable!()
+    }
+}
+
+pub struct RGBA64;
+impl ColorType for RGBA64 {
+    type Inner = u64;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::RGB;
+    const BITS_PER_SAMPLE: &'static [u16] = &[64, 64, 64, 64];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Uint; 4];
+
+    integer_horizontal_predict!();
+}
+
+pub struct RGBA64Float;
+impl ColorType for RGBA64Float {
+    type Inner = f64;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::RGB;
+    const BITS_PER_SAMPLE: &'static [u16] = &[64, 64, 64, 64];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::IEEEFP; 4];
+    fn horizontal_predict(_: &[Self::Inner], _: &mut Vec<Self::Inner>) {
+        unreachable!()
+    }
 }
 
 pub struct CMYK8;
@@ -57,4 +273,81 @@ impl ColorType for CMYK8 {
     type Inner = u8;
     const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::CMYK;
     const BITS_PER_SAMPLE: &'static [u16] = &[8, 8, 8, 8];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Uint; 4];
+
+    integer_horizontal_predict!();
+}
+
+pub struct CMYK16;
+impl ColorType for CMYK16 {
+    type Inner = u16;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::CMYK;
+    const BITS_PER_SAMPLE: &'static [u16] = &[16, 16, 16, 16];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Uint; 4];
+
+    integer_horizontal_predict!();
+}
+
+pub struct CMYK32;
+impl ColorType for CMYK32 {
+    type Inner = u32;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::CMYK;
+    const BITS_PER_SAMPLE: &'static [u16] = &[32, 32, 32, 32];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Uint; 4];
+
+    integer_horizontal_predict!();
+}
+
+pub struct CMYK32Float;
+impl ColorType for CMYK32Float {
+    type Inner = f32;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::CMYK;
+    const BITS_PER_SAMPLE: &'static [u16] = &[32, 32, 32, 32];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::IEEEFP; 4];
+
+    fn horizontal_predict(_: &[Self::Inner], _: &mut Vec<Self::Inner>) {
+        unreachable!()
+    }
+}
+
+pub struct CMYK64;
+impl ColorType for CMYK64 {
+    type Inner = u64;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::CMYK;
+    const BITS_PER_SAMPLE: &'static [u16] = &[64, 64, 64, 64];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Uint; 4];
+
+    integer_horizontal_predict!();
+}
+
+pub struct CMYK64Float;
+impl ColorType for CMYK64Float {
+    type Inner = f64;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::CMYK;
+    const BITS_PER_SAMPLE: &'static [u16] = &[64, 64, 64, 64];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::IEEEFP; 4];
+
+    fn horizontal_predict(_: &[Self::Inner], _: &mut Vec<Self::Inner>) {
+        unreachable!()
+    }
+}
+
+pub struct YCbCr8;
+impl ColorType for YCbCr8 {
+    type Inner = u8;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::YCbCr;
+    const BITS_PER_SAMPLE: &'static [u16] = &[8, 8, 8];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Uint; 3];
+
+    integer_horizontal_predict!();
+}
+
+pub struct CMYKA8;
+impl ColorType for CMYKA8 {
+    type Inner = u8;
+    const TIFF_VALUE: PhotometricInterpretation = PhotometricInterpretation::CMYK;
+    const BITS_PER_SAMPLE: &'static [u16] = &[8, 8, 8, 8, 8];
+    const SAMPLE_FORMAT: &'static [SampleFormat] = &[SampleFormat::Uint; 5];
+
+    integer_horizontal_predict!();
 }

src/encoder/compression/deflate.rs

@@ -0,0 +1,82 @@
+use crate::encoder::compression::*;
+use flate2::{write::ZlibEncoder, Compression as FlateCompression};
+
+/// The Deflate algorithm used to compress image data in TIFF files.
+#[derive(Debug, Clone, Copy)]
+pub struct Deflate {
+    level: FlateCompression,
+}
+
+/// The level of compression used by the Deflate algorithm.
+/// It allows trading compression ratio for compression speed.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+#[non_exhaustive]
+pub enum DeflateLevel {
+    /// The fastest possible compression mode.
+    Fast = 1,
+    /// The conserative choice between speed and ratio.
+    Balanced = 6,
+    /// The best compression available with Deflate.
+    Best = 9,
+}
+
+impl Default for DeflateLevel {
+    fn default() -> Self {
+        DeflateLevel::Balanced
+    }
+}
+
+impl Deflate {
+    /// Create a new deflate compressor with a specific level of compression.
+    pub fn with_level(level: DeflateLevel) -> Self {
+        Self {
+            level: FlateCompression::new(level as u32),
+        }
+    }
+}
+
+impl Default for Deflate {
+    fn default() -> Self {
+        Self::with_level(DeflateLevel::default())
+    }
+}
+
+impl Compression for Deflate {
+    const COMPRESSION_METHOD: CompressionMethod = CompressionMethod::Deflate;
+
+    fn get_algorithm(&self) -> Compressor {
+        Compressor::Deflate(*self)
+    }
+}
+
+impl CompressionAlgorithm for Deflate {
+    fn write_to<W: Write>(&mut self, writer: &mut W, bytes: &[u8]) -> Result<u64, io::Error> {
+        let mut encoder = ZlibEncoder::new(writer, self.level);
+        encoder.write_all(bytes)?;
+        encoder.try_finish()?;
+        Ok(encoder.total_out())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::encoder::compression::tests::TEST_DATA;
+    use std::io::Cursor;
+
+    #[test]
+    fn test_deflate() {
+        const EXPECTED_COMPRESSED_DATA: [u8; 64] = [
+            0x78, 0x9C, 0x15, 0xC7, 0xD1, 0x0D, 0x80, 0x20, 0x0C, 0x04, 0xD0, 0x55, 0x6E, 0x02,
+            0xA7, 0x71, 0x81, 0xA6, 0x41, 0xDA, 0x28, 0xD4, 0xF4, 0xD0, 0xF9, 0x81, 0xE4, 0xFD,
+            0xBC, 0xD3, 0x9C, 0x58, 0x04, 0x1C, 0xE9, 0xBD, 0xE2, 0x8A, 0x84, 0x5A, 0xD1, 0x7B,
+            0xE7, 0x97, 0xF4, 0xF8, 0x08, 0x8D, 0xF6, 0x66, 0x21, 0x3D, 0x3A, 0xE4, 0xA9, 0x91,
+            0x3E, 0xAC, 0xF1, 0x98, 0xB9, 0x70, 0x17, 0x13,
+        ];
+
+        let mut compressed_data = Vec::<u8>::new();
+        let mut writer = Cursor::new(&mut compressed_data);
+        Deflate::default().write_to(&mut writer, TEST_DATA).unwrap();
+        assert_eq!(EXPECTED_COMPRESSED_DATA, compressed_data.as_slice());
+    }
+}

src/encoder/compression/lzw.rs

@@ -0,0 +1,46 @@
+use crate::encoder::compression::*;
+use weezl::encode::Encoder as LZWEncoder;
+
+/// The LZW algorithm used to compress image data in TIFF files.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
+pub struct Lzw;
+
+impl Compression for Lzw {
+    const COMPRESSION_METHOD: CompressionMethod = CompressionMethod::LZW;
+
+    fn get_algorithm(&self) -> Compressor {
+        Compressor::Lzw(*self)
+    }
+}
+
+impl CompressionAlgorithm for Lzw {
+    fn write_to<W: Write>(&mut self, writer: &mut W, bytes: &[u8]) -> Result<u64, io::Error> {
+        let mut encoder = LZWEncoder::with_tiff_size_switch(weezl::BitOrder::Msb, 8);
+        let result = encoder.into_stream(writer).encode_all(bytes);
+        let byte_count = result.bytes_written as u64;
+        result.status.map(|_| byte_count)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::encoder::compression::tests::TEST_DATA;
+    use std::io::Cursor;
+
+    #[test]
+    fn test_lzw() {
+        const EXPECTED_COMPRESSED_DATA: [u8; 63] = [
+            0x80, 0x15, 0x0D, 0x06, 0x93, 0x98, 0x82, 0x08, 0x20, 0x30, 0x88, 0x0E, 0x67, 0x43,
+            0x91, 0xA4, 0xDC, 0x67, 0x10, 0x19, 0x8D, 0xE7, 0x21, 0x01, 0x8C, 0xD0, 0x65, 0x31,
+            0x9A, 0xE1, 0xD1, 0x03, 0xB1, 0x86, 0x1A, 0x6F, 0x3A, 0xC1, 0x4C, 0x66, 0xF3, 0x69,
+            0xC0, 0xE4, 0x65, 0x39, 0x9C, 0xCD, 0x26, 0xF3, 0x74, 0x20, 0xD8, 0x67, 0x89, 0x9A,
+            0x4E, 0x86, 0x83, 0x69, 0xCC, 0x5D, 0x01,
+        ];
+
+        let mut compressed_data = Vec::<u8>::new();
+        let mut writer = Cursor::new(&mut compressed_data);
+        Lzw.write_to(&mut writer, TEST_DATA).unwrap();
+        assert_eq!(EXPECTED_COMPRESSED_DATA, compressed_data.as_slice());
+    }
+}

src/encoder/compression/mod.rs

@@ -0,0 +1,70 @@
+use crate::tags::CompressionMethod;
+use std::io::{self, Write};
+
+#[cfg(feature = "deflate")]
+mod deflate;
+#[cfg(feature = "lzw")]
+mod lzw;
+mod packbits;
+mod uncompressed;
+
+#[cfg(feature = "deflate")]
+pub use self::deflate::{Deflate, DeflateLevel};
+
+#[cfg(feature = "lzw")]
+pub use self::lzw::Lzw;
+
+pub use self::packbits::Packbits;
+pub use self::uncompressed::Uncompressed;
+
+/// An algorithm used for compression
+pub trait CompressionAlgorithm {
+    /// The algorithm writes data directly into the writer.
+    /// It returns the total number of bytes written.
+    fn write_to<W: Write>(&mut self, writer: &mut W, bytes: &[u8]) -> Result<u64, io::Error>;
+}
+
+/// An algorithm used for compression with associated enums and optional configurations.
+pub trait Compression: CompressionAlgorithm {
+    /// The corresponding tag to the algorithm.
+    const COMPRESSION_METHOD: CompressionMethod;
+
+    /// Method to optain a type that can store each variant of comression algorithm.
+    fn get_algorithm(&self) -> Compressor;
+}
+
+/// An enum to store each compression algorithm.
+#[non_exhaustive]
+pub enum Compressor {
+    Uncompressed(Uncompressed),
+    #[cfg(feature = "lzw")]
+    Lzw(Lzw),
+    #[cfg(feature = "deflate")]
+    Deflate(Deflate),
+    Packbits(Packbits),
+}
+
+impl Default for Compressor {
+    /// The default compression strategy does not apply any compression.
+    fn default() -> Self {
+        Compressor::Uncompressed(Uncompressed)
+    }
+}
+
+impl CompressionAlgorithm for Compressor {
+    fn write_to<W: Write>(&mut self, writer: &mut W, bytes: &[u8]) -> Result<u64, io::Error> {
+        match self {
+            Compressor::Uncompressed(algorithm) => algorithm.write_to(writer, bytes),
+            #[cfg(feature = "lzw")]
+            Compressor::Lzw(algorithm) => algorithm.write_to(writer, bytes),
+            #[cfg(feature = "deflate")]
+            Compressor::Deflate(algorithm) => algorithm.write_to(writer, bytes),
+            Compressor::Packbits(algorithm) => algorithm.write_to(writer, bytes),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    pub const TEST_DATA: &[u8] = b"This is a string for checking various compression algorithms.";
+}

src/encoder/compression/packbits.rs

@@ -0,0 +1,204 @@
+use crate::encoder::compression::*;
+use std::io::{BufWriter, Error, ErrorKind};
+
+/// Compressor that uses the Packbits[^note] algorithm to compress bytes.
+///
+/// [^note]: PackBits is often ineffective on continuous tone images,
+///          including many grayscale images. In such cases, it is better
+///          to leave the image uncompressed.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
+pub struct Packbits;
+
+impl Compression for Packbits {
+    const COMPRESSION_METHOD: CompressionMethod = CompressionMethod::PackBits;
+
+    fn get_algorithm(&self) -> Compressor {
+        Compressor::Packbits(*self)
+    }
+}
+
+impl CompressionAlgorithm for Packbits {
+    fn write_to<W: Write>(&mut self, writer: &mut W, bytes: &[u8]) -> Result<u64, io::Error> {
+        // Inspired by https://github.com/skirridsystems/packbits
+
+        const MIN_REPT: u8 = 3; // Minimum run to compress between differ blocks
+        const MAX_BYTES: u8 = 128; // Maximum number of bytes that can be encoded in a header byte
+
+        // Encoding for header byte based on number of bytes represented.
+        fn encode_diff(n: u8) -> u8 {
+            n - 1
+        }
+        fn encode_rept(n: u8) -> u8 {
+            let var = 256 - (n - 1) as u16;
+            var as u8
+        }
+
+        fn write_u8<W: Write>(writer: &mut W, byte: u8) -> Result<u64, Error> {
+            writer.write(&[byte]).map(|byte_count| byte_count as u64)
+        }
+
+        let mut bufwriter = BufWriter::new(writer);
+        let mut bytes_written = 0u64; // The number of bytes written into the writer
+        let mut offset: Option<u64> = None; // The index of the first byte written into the writer
+
+        let mut src_index: usize = 0; // Index of the current byte
+        let mut src_count = bytes.len(); //The number of bytes remaining to be compressed
+
+        let mut in_run = false; // Indication whether counting of similar bytes is performed
+        let mut run_index = 0u8; // Distance into pending bytes that a run starts
+
+        let mut bytes_pending = 0u8; // Bytes looked at but not yet output
+        let mut pending_index = 0usize; // Index of the first pending byte
+
+        let mut curr_byte: u8; // Byte currently being considered
+        let mut last_byte: u8; // Previous byte
+
+        // Need at least one byte to compress
+        if src_count == 0 {
+            return Err(Error::new(ErrorKind::WriteZero, "write zero"));
+        }
+
+        // Prime compressor with first character.
+        last_byte = bytes[src_index];
+        src_index += 1;
+        bytes_pending += 1;
+
+        while src_count - 1 != 0 {
+            src_count -= 1;
+            curr_byte = bytes[src_index];
+            src_index += 1;
+            bytes_pending += 1;
+
+            if in_run {
+                if (curr_byte != last_byte) || (bytes_pending > MAX_BYTES) {
+                    offset.get_or_insert(write_u8(&mut bufwriter, encode_rept(bytes_pending - 1))?);
+                    write_u8(&mut bufwriter, last_byte)?;
+                    bytes_written += 2;
+
+                    bytes_pending = 1;
+                    pending_index = src_index - 1;
+                    run_index = 0;
+                    in_run = false;
+                }
+            } else if bytes_pending > MAX_BYTES {
+                // We have as much differing data as we can output in one chunk.
+                // Output MAX_BYTES leaving one byte.
+                offset.get_or_insert(write_u8(&mut bufwriter, encode_diff(MAX_BYTES))?);
+                bufwriter.write_all(&bytes[pending_index..pending_index + MAX_BYTES as usize])?;
+                bytes_written += 1 + MAX_BYTES as u64;
+
+                pending_index += MAX_BYTES as usize;
+                bytes_pending -= MAX_BYTES;
+                run_index = bytes_pending - 1; // A run could start here
+            } else if curr_byte == last_byte {
+                if (bytes_pending - run_index >= MIN_REPT) || (run_index == 0) {
+                    // This is a worthwhile run
+                    if run_index != 0 {
+                        // Flush differing data out of input buffer
+                        offset.get_or_insert(write_u8(&mut bufwriter, encode_diff(run_index))?);
+                        bufwriter
+                            .write_all(&bytes[pending_index..pending_index + run_index as usize])?;
+                        bytes_written += 1 + run_index as u64;
+                    }
+                    bytes_pending -= run_index; // Length of run
+                    in_run = true;
+                }
+            } else {
+                run_index = bytes_pending - 1; // A run could start here
+            }
+            last_byte = curr_byte;
+        }
+
+        // Output the remainder
+        if in_run {
+            bytes_written += 2;
+            offset.get_or_insert(write_u8(&mut bufwriter, encode_rept(bytes_pending))?);
+            write_u8(&mut bufwriter, last_byte)?;
+        } else {
+            bytes_written += 1 + bytes_pending as u64;
+            offset.get_or_insert(write_u8(&mut bufwriter, encode_diff(bytes_pending))?);
+            bufwriter.write_all(&bytes[pending_index..pending_index + bytes_pending as usize])?;
+        }
+
+        bufwriter.flush()?;
+        Ok(bytes_written)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::encoder::compression::tests::TEST_DATA;
+    use std::io::Cursor;
+
+    #[test]
+    fn test_packbits_single_byte() {
+        // compress single byte
+        const UNCOMPRESSED_DATA: [u8; 1] = [0x3F];
+        const EXPECTED_COMPRESSED_DATA: [u8; 2] = [0x00, 0x3F];
+
+        let mut compressed_data = Vec::<u8>::new();
+        let mut writer = Cursor::new(&mut compressed_data);
+        Packbits.write_to(&mut writer, &UNCOMPRESSED_DATA).unwrap();
+        assert_eq!(compressed_data, EXPECTED_COMPRESSED_DATA);
+    }
+
+    #[test]
+    fn test_packbits_rept() {
+        // compress buffer with repetitive sequence
+        const UNCOMPRESSED_DATA: &[u8] =
+            b"This strrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrring hangs.";
+        const EXPECTED_COMPRESSED_DATA: &[u8] = b"\x06This st\xD1r\x09ing hangs.";
+
+        let mut compressed_data = Vec::<u8>::new();
+        let mut writer = Cursor::new(&mut compressed_data);
+        Packbits.write_to(&mut writer, UNCOMPRESSED_DATA).unwrap();
+        assert_eq!(compressed_data, EXPECTED_COMPRESSED_DATA);
+    }
+
+    #[test]
+    fn test_packbits_large_rept_nonrept() {
+        // compress buffer with large repetitive and non-repetitive sequence
+        let mut data = b"This st".to_vec();
+        for _i in 0..158 {
+            data.push(b'r');
+        }
+        data.extend_from_slice(b"ing hangs.");
+        for i in 0..158 {
+            data.push(i);
+        }
+
+        const EXPECTED_COMPRESSED_DATA: [u8; 182] = [
+            0x06, 0x54, 0x68, 0x69, 0x73, 0x20, 0x73, 0x74, 0x81, 0x72, 0xE3, 0x72, 0x7F, 0x69,
+            0x6E, 0x67, 0x20, 0x68, 0x61, 0x6E, 0x67, 0x73, 0x2E, 0x00, 0x01, 0x02, 0x03, 0x04,
+            0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12,
+            0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20,
+            0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E,
+            0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C,
+            0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A,
+            0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
+            0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66,
+            0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74,
+            0x75, 0x27, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F, 0x80, 0x81,
+            0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F,
+            0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D,
+        ];
+
+        let mut compressed_data = Vec::<u8>::new();
+        let mut writer = Cursor::new(&mut compressed_data);
+        Packbits.write_to(&mut writer, data.as_slice()).unwrap();
+        assert_eq!(compressed_data, EXPECTED_COMPRESSED_DATA);
+    }
+
+    #[test]
+    fn test_packbits() {
+        // compress teststring
+        const EXPECTED_COMPRESSED_DATA: &[u8] =
+            b"\x3CThis is a string for checking various compression algorithms.";
+
+        let mut compressed_data = Vec::<u8>::new();
+        let mut writer = Cursor::new(&mut compressed_data);
+        Packbits.write_to(&mut writer, TEST_DATA).unwrap();
+        assert_eq!(compressed_data, EXPECTED_COMPRESSED_DATA);
+    }
+}

src/encoder/compression/uncompressed.rs

@@ -0,0 +1,34 @@
+use crate::encoder::compression::*;
+
+/// The default algorithm which does not compress at all.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
+pub struct Uncompressed;
+
+impl Compression for Uncompressed {
+    const COMPRESSION_METHOD: CompressionMethod = CompressionMethod::None;
+
+    fn get_algorithm(&self) -> Compressor {
+        Compressor::Uncompressed(*self)
+    }
+}
+
+impl CompressionAlgorithm for Uncompressed {
+    fn write_to<W: Write>(&mut self, writer: &mut W, bytes: &[u8]) -> Result<u64, io::Error> {
+        writer.write(bytes).map(|byte_count| byte_count as u64)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::encoder::compression::tests::TEST_DATA;
+    use std::io::Cursor;
+
+    #[test]
+    fn test_no_compression() {
+        let mut compressed_data = Vec::<u8>::new();
+        let mut writer = Cursor::new(&mut compressed_data);
+        Uncompressed.write_to(&mut writer, TEST_DATA).unwrap();
+        assert_eq!(TEST_DATA, compressed_data);
+    }
+}

src/encoder/tiff_value.rs

@@ -0,0 +1,523 @@
+use std::{borrow::Cow, io::Write, slice::from_ref};
+
+use crate::{bytecast, tags::Type, TiffError, TiffFormatError, TiffResult};
+
+use super::writer::TiffWriter;
+
+/// Trait for types that can be encoded in a tiff file
+pub trait TiffValue {
+    const BYTE_LEN: u8;
+    const FIELD_TYPE: Type;
+    fn count(&self) -> usize;
+    fn bytes(&self) -> usize {
+        self.count() * usize::from(Self::BYTE_LEN)
+    }
+
+    /// Access this value as an contiguous sequence of bytes.
+    /// If their is no trivial representation, allocate it on the heap.
+    fn data(&self) -> Cow<[u8]>;
+
+    /// Write this value to a TiffWriter.
+    /// While the default implementation will work in all cases, it may require unnecessary allocations.
+    /// The written bytes of any custom implementation MUST be the same as yielded by `self.data()`.
+    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
+        writer.write_bytes(&self.data())?;
+        Ok(())
+    }
+}
+
+impl TiffValue for [u8] {
+    const BYTE_LEN: u8 = 1;
+    const FIELD_TYPE: Type = Type::BYTE;
+
+    fn count(&self) -> usize {
+        self.len()
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(self)
+    }
+}
+
+impl TiffValue for [i8] {
+    const BYTE_LEN: u8 = 1;
+    const FIELD_TYPE: Type = Type::SBYTE;
+
+    fn count(&self) -> usize {
+        self.len()
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::i8_as_ne_bytes(self))
+    }
+}
+
+impl TiffValue for [u16] {
+    const BYTE_LEN: u8 = 2;
+    const FIELD_TYPE: Type = Type::SHORT;
+
+    fn count(&self) -> usize {
+        self.len()
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::u16_as_ne_bytes(self))
+    }
+}
+
+impl TiffValue for [i16] {
+    const BYTE_LEN: u8 = 2;
+    const FIELD_TYPE: Type = Type::SSHORT;
+
+    fn count(&self) -> usize {
+        self.len()
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::i16_as_ne_bytes(self))
+    }
+}
+
+impl TiffValue for [u32] {
+    const BYTE_LEN: u8 = 4;
+    const FIELD_TYPE: Type = Type::LONG;
+
+    fn count(&self) -> usize {
+        self.len()
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::u32_as_ne_bytes(self))
+    }
+}
+
+impl TiffValue for [i32] {
+    const BYTE_LEN: u8 = 4;
+    const FIELD_TYPE: Type = Type::SLONG;
+
+    fn count(&self) -> usize {
+        self.len()
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::i32_as_ne_bytes(self))
+    }
+}
+
+impl TiffValue for [u64] {
+    const BYTE_LEN: u8 = 8;
+    const FIELD_TYPE: Type = Type::LONG8;
+
+    fn count(&self) -> usize {
+        self.len()
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::u64_as_ne_bytes(self))
+    }
+}
+
+impl TiffValue for [i64] {
+    const BYTE_LEN: u8 = 8;
+    const FIELD_TYPE: Type = Type::SLONG8;
+
+    fn count(&self) -> usize {
+        self.len()
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::i64_as_ne_bytes(self))
+    }
+}
+
+impl TiffValue for [f32] {
+    const BYTE_LEN: u8 = 4;
+    const FIELD_TYPE: Type = Type::FLOAT;
+
+    fn count(&self) -> usize {
+        self.len()
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        // We write using native endian so this should be safe
+        Cow::Borrowed(bytecast::f32_as_ne_bytes(self))
+    }
+}
+
+impl TiffValue for [f64] {
+    const BYTE_LEN: u8 = 8;
+    const FIELD_TYPE: Type = Type::DOUBLE;
+
+    fn count(&self) -> usize {
+        self.len()
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        // We write using native endian so this should be safe
+        Cow::Borrowed(bytecast::f64_as_ne_bytes(self))
+    }
+}
+
+impl TiffValue for u8 {
+    const BYTE_LEN: u8 = 1;
+    const FIELD_TYPE: Type = Type::BYTE;
+
+    fn count(&self) -> usize {
+        1
+    }
+
+    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
+        writer.write_u8(*self)?;
+        Ok(())
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(from_ref(self))
+    }
+}
+
+impl TiffValue for i8 {
+    const BYTE_LEN: u8 = 1;
+    const FIELD_TYPE: Type = Type::SBYTE;
+
+    fn count(&self) -> usize {
+        1
+    }
+
+    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
+        writer.write_i8(*self)?;
+        Ok(())
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::i8_as_ne_bytes(from_ref(self)))
+    }
+}
+
+impl TiffValue for u16 {
+    const BYTE_LEN: u8 = 2;
+    const FIELD_TYPE: Type = Type::SHORT;
+
+    fn count(&self) -> usize {
+        1
+    }
+
+    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
+        writer.write_u16(*self)?;
+        Ok(())
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::u16_as_ne_bytes(from_ref(self)))
+    }
+}
+
+impl TiffValue for i16 {
+    const BYTE_LEN: u8 = 2;
+    const FIELD_TYPE: Type = Type::SSHORT;
+
+    fn count(&self) -> usize {
+        1
+    }
+
+    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
+        writer.write_i16(*self)?;
+        Ok(())
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::i16_as_ne_bytes(from_ref(self)))
+    }
+}
+
+impl TiffValue for u32 {
+    const BYTE_LEN: u8 = 4;
+    const FIELD_TYPE: Type = Type::LONG;
+
+    fn count(&self) -> usize {
+        1
+    }
+
+    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
+        writer.write_u32(*self)?;
+        Ok(())
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::u32_as_ne_bytes(from_ref(self)))
+    }
+}
+
+impl TiffValue for i32 {
+    const BYTE_LEN: u8 = 4;
+    const FIELD_TYPE: Type = Type::SLONG;
+
+    fn count(&self) -> usize {
+        1
+    }
+
+    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
+        writer.write_i32(*self)?;
+        Ok(())
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::i32_as_ne_bytes(from_ref(self)))
+    }
+}
+
+impl TiffValue for u64 {
+    const BYTE_LEN: u8 = 8;
+    const FIELD_TYPE: Type = Type::LONG8;
+
+    fn count(&self) -> usize {
+        1
+    }
+
+    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
+        writer.write_u64(*self)?;
+        Ok(())
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::u64_as_ne_bytes(from_ref(self)))
+    }
+}
+
+impl TiffValue for i64 {
+    const BYTE_LEN: u8 = 8;
+    const FIELD_TYPE: Type = Type::SLONG8;
+
+    fn count(&self) -> usize {
+        1
+    }
+
+    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
+        writer.write_i64(*self)?;
+        Ok(())
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::i64_as_ne_bytes(from_ref(self)))
+    }
+}
+
+impl TiffValue for f32 {
+    const BYTE_LEN: u8 = 4;
+    const FIELD_TYPE: Type = Type::FLOAT;
+
+    fn count(&self) -> usize {
+        1
+    }
+
+    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
+        writer.write_f32(*self)?;
+        Ok(())
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::f32_as_ne_bytes(from_ref(self)))
+    }
+}
+
+impl TiffValue for f64 {
+    const BYTE_LEN: u8 = 8;
+    const FIELD_TYPE: Type = Type::DOUBLE;
+
+    fn count(&self) -> usize {
+        1
+    }
+
+    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
+        writer.write_f64(*self)?;
+        Ok(())
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::f64_as_ne_bytes(from_ref(self)))
+    }
+}
+
+impl TiffValue for Ifd {
+    const BYTE_LEN: u8 = 4;
+    const FIELD_TYPE: Type = Type::IFD;
+
+    fn count(&self) -> usize {
+        1
+    }
+
+    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
+        writer.write_u32(self.0)?;
+        Ok(())
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::u32_as_ne_bytes(from_ref(&self.0)))
+    }
+}
+
+impl TiffValue for Ifd8 {
+    const BYTE_LEN: u8 = 8;
+    const FIELD_TYPE: Type = Type::IFD8;
+
+    fn count(&self) -> usize {
+        1
+    }
+
+    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
+        writer.write_u64(self.0)?;
+        Ok(())
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::u64_as_ne_bytes(from_ref(&self.0)))
+    }
+}
+
+impl TiffValue for Rational {
+    const BYTE_LEN: u8 = 8;
+    const FIELD_TYPE: Type = Type::RATIONAL;
+
+    fn count(&self) -> usize {
+        1
+    }
+
+    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
+        writer.write_u32(self.n)?;
+        writer.write_u32(self.d)?;
+        Ok(())
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Owned({
+            let first_dword = bytecast::u32_as_ne_bytes(from_ref(&self.n));
+            let second_dword = bytecast::u32_as_ne_bytes(from_ref(&self.d));
+            [first_dword, second_dword].concat()
+        })
+    }
+}
+
+impl TiffValue for SRational {
+    const BYTE_LEN: u8 = 8;
+    const FIELD_TYPE: Type = Type::SRATIONAL;
+
+    fn count(&self) -> usize {
+        1
+    }
+
+    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
+        writer.write_i32(self.n)?;
+        writer.write_i32(self.d)?;
+        Ok(())
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Owned({
+            let first_dword = bytecast::i32_as_ne_bytes(from_ref(&self.n));
+            let second_dword = bytecast::i32_as_ne_bytes(from_ref(&self.d));
+            [first_dword, second_dword].concat()
+        })
+    }
+}
+
+impl TiffValue for str {
+    const BYTE_LEN: u8 = 1;
+    const FIELD_TYPE: Type = Type::ASCII;
+
+    fn count(&self) -> usize {
+        self.len() + 1
+    }
+
+    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
+        if self.is_ascii() && !self.bytes().any(|b| b == 0) {
+            writer.write_bytes(self.as_bytes())?;
+            writer.write_u8(0)?;
+            Ok(())
+        } else {
+            Err(TiffError::FormatError(TiffFormatError::InvalidTag))
+        }
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Owned({
+            if self.is_ascii() && !self.bytes().any(|b| b == 0) {
+                let bytes: &[u8] = self.as_bytes();
+                [bytes, &[0]].concat()
+            } else {
+                vec![]
+            }
+        })
+    }
+}
+
+impl<'a, T: TiffValue + ?Sized> TiffValue for &'a T {
+    const BYTE_LEN: u8 = T::BYTE_LEN;
+    const FIELD_TYPE: Type = T::FIELD_TYPE;
+
+    fn count(&self) -> usize {
+        (*self).count()
+    }
+
+    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
+        (*self).write(writer)
+    }
+
+    fn data(&self) -> Cow<[u8]> {
+        T::data(self)
+    }
+}
+
+macro_rules! impl_tiff_value_for_contiguous_sequence {
+    ($inner_type:ty; $bytes:expr; $field_type:expr) => {
+        impl $crate::encoder::TiffValue for [$inner_type] {
+            const BYTE_LEN: u8 = $bytes;
+            const FIELD_TYPE: Type = $field_type;
+
+            fn count(&self) -> usize {
+                self.len()
+            }
+
+            fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
+                for x in self {
+                    x.write(writer)?;
+                }
+                Ok(())
+            }
+
+            fn data(&self) -> Cow<[u8]> {
+                let mut buf: Vec<u8> = Vec::with_capacity(Self::BYTE_LEN as usize * self.len());
+                for x in self {
+                    buf.extend_from_slice(&x.data());
+                }
+                Cow::Owned(buf)
+            }
+        }
+    };
+}
+
+impl_tiff_value_for_contiguous_sequence!(Ifd; 4; Type::IFD);
+impl_tiff_value_for_contiguous_sequence!(Ifd8; 8; Type::IFD8);
+impl_tiff_value_for_contiguous_sequence!(Rational; 8; Type::RATIONAL);
+impl_tiff_value_for_contiguous_sequence!(SRational; 8; Type::SRATIONAL);
+
+/// Type to represent tiff values of type `IFD`
+#[derive(Clone)]
+pub struct Ifd(pub u32);
+
+/// Type to represent tiff values of type `IFD8`
+#[derive(Clone)]
+pub struct Ifd8(pub u64);
+
+/// Type to represent tiff values of type `RATIONAL`
+#[derive(Clone)]
+pub struct Rational {
+    pub n: u32,
+    pub d: u32,
+}
+
+/// Type to represent tiff values of type `SRATIONAL`
+#[derive(Clone)]
+pub struct SRational {
+    pub n: i32,
+    pub d: i32,
+}

src/encoder/writer.rs

@@ -1,94 +1,172 @@
-use error::TiffResult;
-use byteorder::{BigEndian, ByteOrder, LittleEndian, NativeEndian, WriteBytesExt};
+use crate::encoder::compression::*;
+use crate::error::TiffResult;
 use std::io::{self, Seek, SeekFrom, Write};
 
-pub trait TiffByteOrder: ByteOrder {
-    fn write_header<W: Write>(writer: &mut TiffWriter<W>) -> TiffResult<()>;
+pub fn write_tiff_header<W: Write>(writer: &mut TiffWriter<W>) -> TiffResult<()> {
+    #[cfg(target_endian = "little")]
+    let boi: u8 = 0x49;
+    #[cfg(not(target_endian = "little"))]
+    let boi: u8 = 0x4d;
+
+    writer.writer.write_all(&[boi, boi])?;
+    writer.writer.write_all(&42u16.to_ne_bytes())?;
+    writer.offset += 4;
+
+    Ok(())
 }
 
-impl TiffByteOrder for LittleEndian {
-    fn write_header<W: Write>(writer: &mut TiffWriter<W>) -> TiffResult<()> {
-        writer.writer.write_u16::<LittleEndian>(0x4949)?;
-        writer.writer.write_u16::<LittleEndian>(42)?;
-        writer.offset += 4;
+/// Writes a BigTiff header, excluding the IFD offset field.
+///
+/// Writes the byte order, version number, offset byte size, and zero constant fields. Does
+// _not_ write the offset to the first IFD, this should be done by the caller.
+pub fn write_bigtiff_header<W: Write>(writer: &mut TiffWriter<W>) -> TiffResult<()> {
+    #[cfg(target_endian = "little")]
+    let boi: u8 = 0x49;
+    #[cfg(not(target_endian = "little"))]
+    let boi: u8 = 0x4d;
 
-        Ok(())
-    }
-}
+    // byte order indication
+    writer.writer.write_all(&[boi, boi])?;
+    // version number
+    writer.writer.write_all(&43u16.to_ne_bytes())?;
+    // bytesize of offsets (pointer size)
+    writer.writer.write_all(&8u16.to_ne_bytes())?;
+    // always 0
+    writer.writer.write_all(&0u16.to_ne_bytes())?;
 
-impl TiffByteOrder for BigEndian {
-    fn write_header<W: Write>(writer: &mut TiffWriter<W>) -> TiffResult<()> {
-        writer.writer.write_u16::<BigEndian>(0x4d4d)?;
-        writer.writer.write_u16::<BigEndian>(42)?;
-        writer.offset += 4;
+    // we wrote 8 bytes, so set the internal offset accordingly
+    writer.offset += 8;
 
-        Ok(())
-    }
+    Ok(())
 }
 
 pub struct TiffWriter<W> {
     writer: W,
     offset: u64,
+    byte_count: u64,
+    compressor: Compressor,
 }
 
 impl<W: Write> TiffWriter<W> {
     pub fn new(writer: W) -> Self {
-        Self { writer, offset: 0 }
+        Self {
+            writer,
+            offset: 0,
+            byte_count: 0,
+            compressor: Compressor::default(),
+        }
+    }
+
+    pub fn set_compression(&mut self, compressor: Compressor) {
+        self.compressor = compressor;
+    }
+
+    pub fn reset_compression(&mut self) {
+        self.compressor = Compressor::default();
     }
 
     pub fn offset(&self) -> u64 {
         self.offset
     }
 
+    pub(crate) fn previous_ifd_pointer<K: super::TiffKind>(&self) -> u64 {
+        self.offset() - core::mem::size_of::<K::OffsetType>() as u64
+    }
+
+    pub fn last_written(&self) -> u64 {
+        self.byte_count
+    }
+
     pub fn write_bytes(&mut self, bytes: &[u8]) -> Result<(), io::Error> {
-        self.writer.write_all(bytes)?;
-        self.offset += bytes.len() as u64;
+        self.byte_count = self.compressor.write_to(&mut self.writer, bytes)?;
+        self.offset += self.byte_count;
         Ok(())
     }
 
     pub fn write_u8(&mut self, n: u8) -> Result<(), io::Error> {
-        self.writer.write_u8(n)?;
-        self.offset += 1;
+        self.byte_count = self
+            .compressor
+            .write_to(&mut self.writer, &n.to_ne_bytes())?;
+        self.offset += self.byte_count;
         Ok(())
     }
 
     pub fn write_i8(&mut self, n: i8) -> Result<(), io::Error> {
-        self.writer.write_i8(n)?;
-        self.offset += 1;
+        self.byte_count = self
+            .compressor
+            .write_to(&mut self.writer, &n.to_ne_bytes())?;
+        self.offset += self.byte_count;
         Ok(())
     }
 
     pub fn write_u16(&mut self, n: u16) -> Result<(), io::Error> {
-        self.writer.write_u16::<NativeEndian>(n)?;
-        self.offset += 2;
+        self.byte_count = self
+            .compressor
+            .write_to(&mut self.writer, &n.to_ne_bytes())?;
+        self.offset += self.byte_count;
 
         Ok(())
     }
 
     pub fn write_i16(&mut self, n: i16) -> Result<(), io::Error> {
-        self.writer.write_i16::<NativeEndian>(n)?;
-        self.offset += 2;
+        self.byte_count = self
+            .compressor
+            .write_to(&mut self.writer, &n.to_ne_bytes())?;
+        self.offset += self.byte_count;
 
         Ok(())
     }
 
     pub fn write_u32(&mut self, n: u32) -> Result<(), io::Error> {
-        self.writer.write_u32::<NativeEndian>(n)?;
-        self.offset += 4;
+        self.byte_count = self
+            .compressor
+            .write_to(&mut self.writer, &n.to_ne_bytes())?;
+        self.offset += self.byte_count;
 
         Ok(())
     }
 
     pub fn write_i32(&mut self, n: i32) -> Result<(), io::Error> {
-        self.writer.write_i32::<NativeEndian>(n)?;
-        self.offset += 4;
+        self.byte_count = self
+            .compressor
+            .write_to(&mut self.writer, &n.to_ne_bytes())?;
+        self.offset += self.byte_count;
 
         Ok(())
     }
 
     pub fn write_u64(&mut self, n: u64) -> Result<(), io::Error> {
-        self.writer.write_u64::<NativeEndian>(n)?;
-        self.offset += 8;
+        self.byte_count = self
+            .compressor
+            .write_to(&mut self.writer, &n.to_ne_bytes())?;
+        self.offset += self.byte_count;
+
+        Ok(())
+    }
+
+    pub fn write_i64(&mut self, n: i64) -> Result<(), io::Error> {
+        self.byte_count = self
+            .compressor
+            .write_to(&mut self.writer, &n.to_ne_bytes())?;
+        self.offset += self.byte_count;
+
+        Ok(())
+    }
+
+    pub fn write_f32(&mut self, n: f32) -> Result<(), io::Error> {
+        self.byte_count = self
+            .compressor
+            .write_to(&mut self.writer, &u32::to_ne_bytes(n.to_bits()))?;
+        self.offset += self.byte_count;
+
+        Ok(())
+    }
+
+    pub fn write_f64(&mut self, n: f64) -> Result<(), io::Error> {
+        self.byte_count = self
+            .compressor
+            .write_to(&mut self.writer, &u64::to_ne_bytes(n.to_bits()))?;
+        self.offset += self.byte_count;
 
         Ok(())
     }
@@ -108,7 +186,7 @@ impl<W: Write> TiffWriter<W> {
 impl<W: Seek> TiffWriter<W> {
     pub fn goto_offset(&mut self, offset: u64) -> Result<(), io::Error> {
         self.offset = offset;
-        self.writer.seek(SeekFrom::Start(offset as u64))?;
+        self.writer.seek(SeekFrom::Start(offset))?;
         Ok(())
     }
 }

src/error.rs

@@ -1,198 +1,195 @@
-use std::error::Error;
-use std::fmt;
 use std::io;
+use std::str;
 use std::string;
 
-use decoder::ifd::{Tag, Value};
-use decoder::{CompressionMethod, PhotometricInterpretation, PlanarConfiguration};
-use miniz_oxide::inflate::TINFLStatus;
-use ColorType;
+use quick_error::quick_error;
 
-/// Tiff error kinds.
-#[derive(Debug)]
-pub enum TiffError {
-    /// The Image is not formatted properly.
-    FormatError(TiffFormatError),
+use crate::decoder::ChunkType;
+use crate::tags::{
+    CompressionMethod, PhotometricInterpretation, PlanarConfiguration, SampleFormat, Tag,
+};
+use crate::ColorType;
 
+quick_error! {
+    /// Tiff error kinds.
+    #[derive(Debug)]
+    pub enum TiffError {
+        /// The Image is not formatted properly.
+        FormatError(err: TiffFormatError) {
+            display("format error: {err}")
+            from()
+            source(err)
+        }
+        /// The Decoder does not support features required by the image.
+        UnsupportedError(err: TiffUnsupportedError) {
+            display("unsupported error: {err}")
+            from()
+            source(err)
+        }
+        /// An I/O Error occurred while decoding the image.
+        IoError(err: io::Error) {
+            display("{err}")
+            from()
+            source(err)
+        }
+        /// The Limits of the Decoder is exceeded.
+        LimitsExceeded {
+            display("decoder limits exceeded")
+        }
+        /// An integer conversion to or from a platform size failed.
+        IntSizeError {
+            display("platform or format size limits exceeded")
+        }
+        /// The image does not support the requested operation
+        UsageError(err: UsageError) {
+            display("usage error: {err}")
+            from()
+            source(err)
+        }
+    }
+}
+
+quick_error! {
+    /// The image is not formatted properly.
+    ///
+    /// This indicates that the encoder producing the image might behave incorrectly or that the
+    /// input file has been corrupted.
+    #[derive(Debug, Clone, PartialEq)]
+    #[non_exhaustive]
+    pub enum TiffFormatError {
+        TiffSignatureNotFound {
+            display("TIFF signature not found")
+        }
+        TiffSignatureInvalid {
+            display("TIFF signature invalid")
+        }
+        ImageFileDirectoryNotFound {
+            display("image file directory not found")
+        }
+        InconsistentSizesEncountered {
+            display("inconsistent sizes encountered")
+        }
+        InvalidDimensions(width: u32, height: u32) {
+            display("invalid dimensions: {width}x{height}")
+        }
+        InvalidTag {
+            display("image contains invalid tag")
+        }
+        InvalidTagValueType(tag: Tag) {
+            display("tag `{tag:?}` did not have the expected value type")
+        }
+        RequiredTagNotFound(tag: Tag) {
+            display("required tag `{tag:?}` not found")
+        }
+        UnknownPredictor(pred: u16) {
+            display("unknown predictor “{pred}” encountered")
+        }
+        UnknownPlanarConfiguration(cfg: u16) {
+            display("unknown planar configuration “{cfg}”")
+        }
+        InvalidTypeForTag {
+            display("tag has invalid type")
+        }
+        StripTileTagConflict {
+            display("file should contain either (StripByteCounts and StripOffsets) or (TileByteCounts and TileOffsets), other combination was found")
+        }
+        CycleInOffsets {
+            display("file contained a cycle in the list of IFDs")
+        }
+        SamplesPerPixelIsZero {
+            display("samples per pixel is zero")
+        }
+        CompressedDataCorrupt(message: String) {
+            display("compressed data is corrupt: {message}")
+        }
+    }
+}
+
+quick_error! {
     /// The Decoder does not support features required by the image.
-    UnsupportedError(TiffUnsupportedError),
-
-    /// An I/O Error occurred while decoding the image.
-    IoError(io::Error),
-
-    /// The Limits of the Decoder is exceeded.
-    LimitsExceeded,
-}
-
-/// The image is not formatted properly.
-///
-/// This indicates that the encoder producing the image might behave incorrectly or that the input
-/// file has been corrupted.
-///
-/// The list of variants may grow to incorporate errors of future features. Matching against this
-/// exhaustively is not covered by interface stability guarantees.
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub enum TiffFormatError {
-    TiffSignatureNotFound,
-    TiffSignatureInvalid,
-    ImageFileDirectoryNotFound,
-    InconsistentSizesEncountered,
-    InvalidTag,
-    RequiredTagNotFound(Tag),
-    UnknownPredictor(u32),
-    UnsignedIntegerExpected(Value),
-    SignedIntegerExpected(Value),
-    InflateError(InflateError),
-    #[doc(hidden)]
-    /// Do not match against this variant. It may get removed.
-    __NonExhaustive,
-}
-
-impl fmt::Display for TiffFormatError {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> {
-        use self::TiffFormatError::*;
-        match *self {
-            TiffSignatureNotFound => write!(fmt, "TIFF signature not found."),
-            TiffSignatureInvalid => write!(fmt, "TIFF signature invalid."),
-            ImageFileDirectoryNotFound => write!(fmt, "Image file directory not found."),
-            InconsistentSizesEncountered => write!(fmt, "Inconsistent sizes encountered."),
-            InvalidTag => write!(fmt, "Image contains invalid tag."),
-            RequiredTagNotFound(ref tag) => write!(fmt, "Required tag `{:?}` not found.", tag),
-            UnknownPredictor(ref predictor) => {
-                write!(fmt, "Unknown predictor “{}” encountered", predictor)
-            }
-            UnsignedIntegerExpected(ref val) => {
-                write!(fmt, "Expected unsigned integer, {:?} found.", val)
-            }
-            SignedIntegerExpected(ref val) => {
-                write!(fmt, "Expected signed integer, {:?} found.", val)
-            }
-            InflateError(_) => write!(fmt, "Failed to decode inflate data."),
-            __NonExhaustive => unreachable!(),
+    ///
+    /// This only captures known failures for which the standard either does not require support or an
+    /// implementation has been planned but not yet completed. Some variants may become unused over
+    /// time and will then get deprecated before being removed.
+    #[derive(Debug, Clone, PartialEq, Eq, Hash)]
+    #[non_exhaustive]
+    pub enum TiffUnsupportedError {
+        FloatingPointPredictor(color_type: ColorType) {
+            display("floating point predictor for {color_type:?} is unsupported")
+        }
+        HorizontalPredictor(color_type: ColorType) {
+            display("horizontal predictor for {color_type:?} is unsupported")
+        }
+        InconsistentBitsPerSample(bits_per_sample: Vec<u8>) {
+            display("inconsistent bits per sample: {bits_per_sample:?}")
+        }
+        InterpretationWithBits(interpretation: PhotometricInterpretation, bits_per_sample: Vec<u8>) {
+            display("Photometric interpretation {interpretation:?} with bits per sample {bits_per_sample:?} is unsupported")
+        }
+        UnknownInterpretation {
+            display("unknown photometric interpretation")
+        }
+        UnknownCompressionMethod {
+            display("unknown compression method")
+        }
+        UnsupportedCompressionMethod(method: CompressionMethod) {
+            display("compression method {method:?} is unsupported")
+        }
+        UnsupportedSampleDepth(depth: u8) {
+            display("{depth} samples per pixel is unsupported")
+        }
+        UnsupportedSampleFormat(sample_format: Vec<SampleFormat>) {
+            display("sample format {sample_format:?} is unsupported")
+        }
+        UnsupportedColorType(color_type: ColorType) {
+            display("color type {color_type:?} is unsupported")
+        }
+        UnsupportedBitsPerChannel(bits_per_channel: u8) {
+            display("{bits_per_channel} bits per channel not supported")
+        }
+        UnsupportedPlanarConfig(planar: Option<PlanarConfiguration>) {
+            display("unsupported planar configuration “{planar:?}”")
+        }
+        UnsupportedDataType {
+            display("unsupported data type.")
+        }
+        UnsupportedInterpretation(interpretation: PhotometricInterpretation) {
+            display("unsupported photometric interpretation \"{interpretation:?}\"")
+        }
+        MisalignedTileBoundaries {
+            display("tile rows are not aligned to byte boundaries")
         }
     }
 }
 
-/// Decompression failed due to faulty compressed data.
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct InflateError {
-    status: TINFLStatus,
-}
-
-impl InflateError {
-    pub(crate) fn new(status: TINFLStatus) -> Self {
-        Self { status }
-    }
-}
-
-impl TiffError {
-    pub(crate) fn from_inflate_status(status: TINFLStatus) -> Self {
-        TiffError::FormatError(TiffFormatError::InflateError(InflateError::new(status)))
-    }
-}
-
-/// The Decoder does not support features required by the image.
-///
-/// This only captures known failures for which the standard either does not require support or an
-/// implementation has been planned but not yet completed. Some variants may become unused over
-/// time and will then get deprecated before being removed.
-///
-/// The list of variants may grow. Matching against this exhaustively is not covered by interface
-/// stability guarantees.
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub enum TiffUnsupportedError {
-    HorizontalPredictor(ColorType),
-    InterpretationWithBits(PhotometricInterpretation, Vec<u8>),
-    UnknownInterpretation,
-    UnknownCompressionMethod,
-    UnsupportedCompressionMethod(CompressionMethod),
-    UnsupportedSampleDepth(u8),
-    UnsupportedColorType(ColorType),
-    UnsupportedBitsPerChannel(u8),
-    UnsupportedPlanarConfig(Option<PlanarConfiguration>),
-    UnsupportedDataType,
-    #[doc(hidden)]
-    /// Do not match against this variant. It may get removed.
-    __NonExhaustive,
-}
-
-impl fmt::Display for TiffUnsupportedError {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> {
-        use self::TiffUnsupportedError::*;
-        match *self {
-            HorizontalPredictor(color_type) => write!(
-                fmt,
-                "Horizontal predictor for {:?} is unsupported.",
-                color_type
-            ),
-            InterpretationWithBits(ref photometric_interpretation, ref bits_per_sample) => write!(
-                fmt,
-                "{:?} with {:?} bits per sample is unsupported",
-                photometric_interpretation, bits_per_sample
-            ),
-            UnknownInterpretation => write!(
-                fmt,
-                "The image is using an unknown photometric interpretation."
-            ),
-            UnknownCompressionMethod => write!(fmt, "Unknown compression method."),
-            UnsupportedCompressionMethod(method) => {
-                write!(fmt, "Compression method {:?} is unsupported", method)
-            }
-            UnsupportedSampleDepth(samples) => {
-                write!(fmt, "{} samples per pixel is supported.", samples)
-            }
-            UnsupportedColorType(color_type) => {
-                write!(fmt, "Color type {:?} is unsupported", color_type)
-            }
-            UnsupportedBitsPerChannel(bits) => {
-                write!(fmt, "{} bits per channel not supported", bits)
-            }
-            UnsupportedPlanarConfig(config) => {
-                write!(fmt, "Unsupported planar configuration “{:?}”.", config)
-            }
-            UnsupportedDataType => write!(fmt, "Unsupported data type."),
-            __NonExhaustive => unreachable!(),
+quick_error! {
+    /// User attempted to use the Decoder in a way that is incompatible with a specific image.
+    ///
+    /// For example: attempting to read a tile from a stripped image.
+    #[derive(Debug)]
+    #[non_exhaustive]
+    pub enum UsageError {
+        InvalidChunkType(expected: ChunkType, actual: ChunkType) {
+            display("requested operation is only valid for images with chunk encoding of type {expected:?} but got {actual:?}")
+        }
+        InvalidChunkIndex(index: u32) {
+            display("invalid chunk index ({index}) requested")
+        }
+        PredictorCompressionMismatch {
+            display("requested predictor is not compatible with the requested compression")
+        }
+        PredictorIncompatible {
+            display("the requested predictor is not compatible with the image's format")
+        }
+        PredictorUnavailable {
+            display("the requested predictor is not available")
         }
     }
 }
 
-impl fmt::Display for TiffError {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> {
-        match *self {
-            TiffError::FormatError(ref e) => write!(fmt, "Format error: {}", e),
-            TiffError::UnsupportedError(ref f) => write!(
-                fmt,
-                "The Decoder does not support the \
-                 image format `{}`",
-                f
-            ),
-            TiffError::IoError(ref e) => e.fmt(fmt),
-            TiffError::LimitsExceeded => write!(fmt, "The Decoder limits are exceeded"),
-        }
-    }
-}
-
-impl Error for TiffError {
-    fn description(&self) -> &str {
-        match *self {
-            TiffError::FormatError(..) => "Format error",
-            TiffError::UnsupportedError(..) => "Unsupported error",
-            TiffError::IoError(..) => "IO error",
-            TiffError::LimitsExceeded => "Decoder limits exceeded",
-        }
-    }
-
-    fn cause(&self) -> Option<&dyn Error> {
-        match *self {
-            TiffError::IoError(ref e) => Some(e),
-            _ => None,
-        }
-    }
-}
-
-impl From<io::Error> for TiffError {
-    fn from(err: io::Error) -> TiffError {
-        TiffError::IoError(err)
+impl From<str::Utf8Error> for TiffError {
+    fn from(_err: str::Utf8Error) -> TiffError {
+        TiffError::FormatError(TiffFormatError::InvalidTag)
     }
 }
 
@@ -202,5 +199,25 @@ impl From<string::FromUtf8Error> for TiffError {
     }
 }
 
+impl From<std::num::TryFromIntError> for TiffError {
+    fn from(_err: std::num::TryFromIntError) -> TiffError {
+        TiffError::IntSizeError
+    }
+}
+
+#[cfg(feature = "lzw")]
+impl From<weezl::LzwError> for TiffError {
+    fn from(err: weezl::LzwError) -> TiffError {
+        TiffError::FormatError(TiffFormatError::CompressedDataCorrupt(err.to_string()))
+    }
+}
+
+#[cfg(feature = "jpeg")]
+impl From<zune_jpeg::errors::DecodeErrors> for TiffError {
+    fn from(err: zune_jpeg::errors::DecodeErrors) -> Self {
+        TiffError::FormatError(TiffFormatError::CompressedDataCorrupt(err.to_string()))
+    }
+}
+
 /// Result of an image decoding/encoding process
 pub type TiffResult<T> = Result<T, TiffError>;

src/lib.rs

@@ -4,20 +4,21 @@
 //! lossless and lossy compression.
 //!
 //! # Related Links
-//! * <http://partners.adobe.com/public/developer/tiff/index.html> - The TIFF specification
-
-extern crate byteorder;
-extern crate lzw;
-extern crate miniz_oxide;
+//! * <https://web.archive.org/web/20210108073850/https://www.adobe.io/open/standards/TIFF.html> - The TIFF specification
 
+mod bytecast;
 pub mod decoder;
+mod directory;
 pub mod encoder;
 mod error;
+pub mod tags;
 
-pub use self::error::{InflateError, TiffError, TiffFormatError, TiffResult, TiffUnsupportedError};
+pub use self::directory::Directory;
+pub use self::error::{TiffError, TiffFormatError, TiffResult, TiffUnsupportedError, UsageError};
 
 /// An enumeration over supported color types and their bit depths
 #[derive(Copy, PartialEq, Eq, Debug, Clone, Hash)]
+#[non_exhaustive]
 pub enum ColorType {
     /// Pixel is grayscale
     Gray(u8),
@@ -36,4 +37,28 @@ pub enum ColorType {
 
     /// Pixel is CMYK
     CMYK(u8),
+
+    /// Pixel is CMYK with an alpha channel
+    CMYKA(u8),
+
+    /// Pixel is YCbCr
+    YCbCr(u8),
+
+    /// Pixel has multiple bands/channels
+    Multiband { bit_depth: u8, num_samples: u16 },
+}
+impl ColorType {
+    fn bit_depth(&self) -> u8 {
+        match *self {
+            ColorType::Gray(b)
+            | ColorType::RGB(b)
+            | ColorType::Palette(b)
+            | ColorType::GrayA(b)
+            | ColorType::RGBA(b)
+            | ColorType::CMYK(b)
+            | ColorType::CMYKA(b)
+            | ColorType::YCbCr(b)
+            | ColorType::Multiband { bit_depth: b, .. } => b,
+        }
+    }
 }

src/tags.rs

@@ -0,0 +1,263 @@
+macro_rules! tags {
+    {
+        // Permit arbitrary meta items, which include documentation.
+        $( #[$enum_attr:meta] )*
+        $vis:vis enum $name:ident($ty:tt) $(unknown($unknown_doc:literal))* {
+            // Each of the `Name = Val,` permitting documentation.
+            $($(#[$ident_attr:meta])* $tag:ident = $val:expr,)*
+        }
+    } => {
+        $( #[$enum_attr] )*
+        #[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
+        #[non_exhaustive]
+        pub enum $name {
+            $($(#[$ident_attr])* $tag,)*
+            $(
+                #[doc = $unknown_doc]
+                Unknown($ty),
+            )*
+        }
+
+        impl $name {
+            #[inline(always)]
+            fn __from_inner_type(n: $ty) -> Result<Self, $ty> {
+                match n {
+                    $( $val => Ok($name::$tag), )*
+                    n => Err(n),
+                }
+            }
+
+            #[inline(always)]
+            fn __to_inner_type(&self) -> $ty {
+                match *self {
+                    $( $name::$tag => $val, )*
+                    $( $name::Unknown(n) => { $unknown_doc; n }, )*
+                }
+            }
+        }
+
+        tags!($name, $ty, $($unknown_doc)*);
+    };
+    // For u16 tags, provide direct inherent primitive conversion methods.
+    ($name:tt, u16, $($unknown_doc:literal)*) => {
+        impl $name {
+            #[inline(always)]
+            pub fn from_u16(val: u16) -> Option<Self> {
+                Self::__from_inner_type(val).ok()
+            }
+
+            $(
+            #[inline(always)]
+            pub fn from_u16_exhaustive(val: u16) -> Self {
+                $unknown_doc;
+                Self::__from_inner_type(val).unwrap_or_else(|_| $name::Unknown(val))
+            }
+            )*
+
+            #[inline(always)]
+            pub fn to_u16(&self) -> u16 {
+                Self::__to_inner_type(self)
+            }
+        }
+    };
+    // For other tag types, do nothing for now. With concat_idents one could
+    // provide inherent conversion methods for all types.
+    ($name:tt, $ty:tt, $($unknown_doc:literal)*) => {};
+}
+
+// Note: These tags appear in the order they are mentioned in the TIFF reference
+tags! {
+/// TIFF tags
+pub enum Tag(u16) unknown("A private or extension tag") {
+    // Baseline tags:
+    Artist = 315,
+    // grayscale images PhotometricInterpretation 1 or 3
+    BitsPerSample = 258,
+    CellLength = 265, // TODO add support
+    CellWidth = 264, // TODO add support
+    // palette-color images (PhotometricInterpretation 3)
+    ColorMap = 320, // TODO add support
+    Compression = 259, // TODO add support for 2 and 32773
+    DateTime = 306,
+    ExtraSamples = 338, // TODO add support
+    FillOrder = 266, // TODO add support
+    FreeByteCounts = 289, // TODO add support
+    FreeOffsets = 288, // TODO add support
+    GrayResponseCurve = 291, // TODO add support
+    GrayResponseUnit = 290, // TODO add support
+    HostComputer = 316,
+    ImageDescription = 270,
+    ImageLength = 257,
+    ImageWidth = 256,
+    Make = 271,
+    MaxSampleValue = 281, // TODO add support
+    MinSampleValue = 280, // TODO add support
+    Model = 272,
+    NewSubfileType = 254, // TODO add support
+    Orientation = 274, // TODO add support
+    PhotometricInterpretation = 262,
+    PlanarConfiguration = 284,
+    ResolutionUnit = 296, // TODO add support
+    RowsPerStrip = 278,
+    SamplesPerPixel = 277,
+    Software = 305,
+    StripByteCounts = 279,
+    StripOffsets = 273,
+    SubfileType = 255, // TODO add support
+    Threshholding = 263, // TODO add support
+    XResolution = 282,
+    YResolution = 283,
+    // Advanced tags
+    Predictor = 317,
+    TileWidth = 322,
+    TileLength = 323,
+    TileOffsets = 324,
+    TileByteCounts = 325,
+    SubIfd = 330,
+    // Data Sample Format
+    SampleFormat = 339,
+    SMinSampleValue = 340, // TODO add support
+    SMaxSampleValue = 341, // TODO add support
+    // JPEG
+    JPEGTables = 347,
+    // GeoTIFF
+    ModelPixelScaleTag = 33550, // (SoftDesk)
+    ModelTransformationTag = 34264, // (JPL Carto Group)
+    ModelTiepointTag = 33922, // (Intergraph)
+    // <https://web.archive.org/web/20131111073619/http://www.exif.org/Exif2-1.PDF>
+    // *Do note its typo in the Decimal id*
+    Copyright = 33_432,
+    // <https://web.archive.org/web/20131111073619/http://www.exif.org/Exif2-1.PDF>
+    ExifDirectory = 0x8769,
+    // <https://web.archive.org/web/20131111073619/http://www.exif.org/Exif2-1.PDF>
+    GpsDirectory = 0x8825,
+    GeoKeyDirectoryTag = 34735, // (SPOT)
+    GeoDoubleParamsTag = 34736, // (SPOT)
+    GeoAsciiParamsTag = 34737, // (SPOT)
+    ExifVersion = 0x9000,
+    GdalNodata = 42113, // Contains areas with missing data
+}
+}
+
+/// Identifies the offset of an IFD.
+///
+/// This is represented as a 64-bit integer but only BigTIFF can utilize the bits. It is encoded
+/// as 32-bit unsigned value ([`Type::LONG`]) in regular TIFF files and as 64-bit unsigned value
+/// ([`Type::IFD8`]) in BigTIFF files.
+#[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
+// We could be using `NonZeroU64` here but I find that this complicates semantics. This type
+// represents the integer value stored as a value in a tag. The semantics of treating `0` as an end
+// marker are imposed by the IFD. (It's unclear if Pointer tags such as Exif would allow `0` but in
+// practice it just returns garbage and the validity does not matter greatly to us).
+pub struct IfdPointer(pub u64);
+
+tags! {
+/// The type of an IFD entry (a 2 byte field).
+pub enum Type(u16) {
+    /// 8-bit unsigned integer
+    BYTE = 1,
+    /// 8-bit byte that contains a 7-bit ASCII code; the last byte must be zero
+    ASCII = 2,
+    /// 16-bit unsigned integer
+    SHORT = 3,
+    /// 32-bit unsigned integer
+    LONG = 4,
+    /// Fraction stored as two 32-bit unsigned integers
+    RATIONAL = 5,
+    /// 8-bit signed integer
+    SBYTE = 6,
+    /// 8-bit byte that may contain anything, depending on the field
+    UNDEFINED = 7,
+    /// 16-bit signed integer
+    SSHORT = 8,
+    /// 32-bit signed integer
+    SLONG = 9,
+    /// Fraction stored as two 32-bit signed integers
+    SRATIONAL = 10,
+    /// 32-bit IEEE floating point
+    FLOAT = 11,
+    /// 64-bit IEEE floating point
+    DOUBLE = 12,
+    /// 32-bit unsigned integer (offset)
+    IFD = 13,
+    /// BigTIFF 64-bit unsigned integer
+    LONG8 = 16,
+    /// BigTIFF 64-bit signed integer
+    SLONG8 = 17,
+    /// BigTIFF 64-bit unsigned integer (offset)
+    IFD8 = 18,
+}
+}
+
+tags! {
+/// See [TIFF compression tags](https://www.awaresystems.be/imaging/tiff/tifftags/compression.html)
+/// for reference.
+pub enum CompressionMethod(u16) unknown("A custom compression method") {
+    None = 1,
+    Huffman = 2,
+    Fax3 = 3,
+    Fax4 = 4,
+    LZW = 5,
+    JPEG = 6,
+    // "Extended JPEG" or "new JPEG" style
+    ModernJPEG = 7,
+    Deflate = 8,
+    OldDeflate = 0x80B2,
+    PackBits = 0x8005,
+
+    // Self-assigned by libtiff
+    ZSTD = 0xC350,
+}
+}
+
+tags! {
+pub enum PhotometricInterpretation(u16) {
+    WhiteIsZero = 0,
+    BlackIsZero = 1,
+    RGB = 2,
+    RGBPalette = 3,
+    TransparencyMask = 4,
+    CMYK = 5,
+    YCbCr = 6,
+    CIELab = 8,
+}
+}
+
+tags! {
+pub enum PlanarConfiguration(u16) {
+    Chunky = 1,
+    Planar = 2,
+}
+}
+
+tags! {
+pub enum Predictor(u16) {
+    /// No changes were made to the data
+    None = 1,
+    /// The images' rows were processed to contain the difference of each pixel from the previous one.
+    ///
+    /// This means that instead of having in order `[r1, g1. b1, r2, g2 ...]` you will find
+    /// `[r1, g1, b1, r2-r1, g2-g1, b2-b1, r3-r2, g3-g2, ...]`
+    Horizontal = 2,
+    /// Not currently supported
+    FloatingPoint = 3,
+}
+}
+
+tags! {
+/// Type to represent resolution units
+pub enum ResolutionUnit(u16) {
+    None = 1,
+    Inch = 2,
+    Centimeter = 3,
+}
+}
+
+tags! {
+pub enum SampleFormat(u16) unknown("An unknown extension sample format") {
+    Uint = 1,
+    Int = 2,
+    IEEEFP = 3,
+    Void = 4,
+}
+}

tests/COPYRIGHT

@@ -0,0 +1,4 @@
+subsubifd.tif:
+  url: https://data.kitware.com/api/v1/file/hashsum/sha512/372ca32735c8a8fdbe2286dabead9e779da63f10ba81eda84625e5273f76d74ca1a47a978f67e9c00c12f7f72009c7b2c07a641e643bb0c463812f4ae7f15d6e/download
+  credit: https://github.com/DigitalSlideArchive/tifftools/commit/4d00c70dbce828262f86c1431f7c66b1748965ac
+  license: CC0

tests/benches/README.md

@@ -0,0 +1,4 @@
+Copyrights:
+
+kodim*.png: Eastman Kodak Company, released for unrestricted use
+Transparency.png: Public Domain, according to Wikimedia

tests/decode_bigtiff_images.rs

@@ -0,0 +1,46 @@
+extern crate tiff;
+
+use tiff::decoder::Decoder;
+use tiff::tags::Tag;
+use tiff::ColorType;
+
+use std::fs::File;
+use std::path::PathBuf;
+
+const TEST_IMAGE_DIR: &str = "./tests/images/bigtiff";
+
+#[test]
+fn test_big_tiff() {
+    let filenames = ["BigTIFF.tif", "BigTIFFMotorola.tif", "BigTIFFLong.tif"];
+    for filename in filenames.iter() {
+        let path = PathBuf::from(TEST_IMAGE_DIR).join(filename);
+        let img_file = File::open(path).expect("Cannot find test image!");
+        let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
+        assert_eq!(
+            decoder.dimensions().expect("Cannot get dimensions"),
+            (64, 64)
+        );
+        assert_eq!(
+            decoder.colortype().expect("Cannot get colortype"),
+            ColorType::RGB(8)
+        );
+        assert_eq!(
+            decoder
+                .get_tag_u64(Tag::StripOffsets)
+                .expect("Cannot get StripOffsets"),
+            16
+        );
+        assert_eq!(
+            decoder
+                .get_tag_u64(Tag::RowsPerStrip)
+                .expect("Cannot get RowsPerStrip"),
+            64
+        );
+        assert_eq!(
+            decoder
+                .get_tag_u64(Tag::StripByteCounts)
+                .expect("Cannot get StripByteCounts"),
+            12288
+        )
+    }
+}

tests/decode_fp16_images.rs

@@ -0,0 +1,195 @@
+extern crate tiff;
+
+use tiff::decoder::{Decoder, DecodingResult};
+use tiff::ColorType;
+
+use std::fs::File;
+use std::path::PathBuf;
+
+const TEST_IMAGE_DIR: &str = "./tests/images/";
+
+/// Test a basic all white image
+#[test]
+fn test_white_ieee_fp16() {
+    let filenames = ["white-fp16.tiff"];
+
+    for filename in filenames.iter() {
+        let path = PathBuf::from(TEST_IMAGE_DIR).join(filename);
+        let img_file = File::open(path).expect("Cannot find test image!");
+        let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
+        assert_eq!(
+            decoder.dimensions().expect("Cannot get dimensions"),
+            (256, 256)
+        );
+        assert_eq!(
+            decoder.colortype().expect("Cannot get colortype"),
+            ColorType::Gray(16)
+        );
+        if let DecodingResult::F16(img) = decoder.read_image().unwrap() {
+            for p in img {
+                assert!(p == half::f16::from_f32_const(1.0));
+            }
+        } else {
+            panic!("Wrong data type");
+        }
+    }
+}
+
+/// Test a single black pixel, to make sure scaling is ok
+#[test]
+fn test_one_black_pixel_ieee_fp16() {
+    let filenames = ["single-black-fp16.tiff"];
+
+    for filename in filenames.iter() {
+        let path = PathBuf::from(TEST_IMAGE_DIR).join(filename);
+        let img_file = File::open(path).expect("Cannot find test image!");
+        let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
+        assert_eq!(
+            decoder.dimensions().expect("Cannot get dimensions"),
+            (256, 256)
+        );
+        assert_eq!(
+            decoder.colortype().expect("Cannot get colortype"),
+            ColorType::Gray(16)
+        );
+        if let DecodingResult::F16(img) = decoder.read_image().unwrap() {
+            for (i, p) in img.iter().enumerate() {
+                if i == 0 {
+                    assert!(p < &half::f16::from_f32_const(0.001));
+                } else {
+                    assert!(p == &half::f16::from_f32_const(1.0));
+                }
+            }
+        } else {
+            panic!("Wrong data type");
+        }
+    }
+}
+
+/// Test white with horizontal differencing predictor
+#[test]
+fn test_pattern_horizontal_differencing_ieee_fp16() {
+    let filenames = ["white-fp16-pred2.tiff"];
+
+    for filename in filenames.iter() {
+        let path = PathBuf::from(TEST_IMAGE_DIR).join(filename);
+        let img_file = File::open(path).expect("Cannot find test image!");
+        let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
+        assert_eq!(
+            decoder.dimensions().expect("Cannot get dimensions"),
+            (256, 256)
+        );
+        assert_eq!(
+            decoder.colortype().expect("Cannot get colortype"),
+            ColorType::Gray(16)
+        );
+        if let DecodingResult::F16(img) = decoder.read_image().unwrap() {
+            // 0, 2, 5, 8, 12, 16, 255 are black
+            let black = [0, 2, 5, 8, 12, 16, 255];
+            for (i, p) in img.iter().enumerate() {
+                if black.contains(&i) {
+                    assert!(p < &half::f16::from_f32_const(0.001));
+                } else {
+                    assert!(p == &half::f16::from_f32_const(1.0));
+                }
+            }
+        } else {
+            panic!("Wrong data type");
+        }
+    }
+}
+
+/// Test white with floating point predictor
+#[test]
+fn test_pattern_predictor_ieee_fp16() {
+    let filenames = ["white-fp16-pred3.tiff"];
+
+    for filename in filenames.iter() {
+        let path = PathBuf::from(TEST_IMAGE_DIR).join(filename);
+        let img_file = File::open(path).expect("Cannot find test image!");
+        let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
+        assert_eq!(
+            decoder.dimensions().expect("Cannot get dimensions"),
+            (256, 256)
+        );
+        assert_eq!(
+            decoder.colortype().expect("Cannot get colortype"),
+            ColorType::Gray(16)
+        );
+        if let DecodingResult::F16(img) = decoder.read_image().unwrap() {
+            // 0, 2, 5, 8, 12, 16, 255 are black
+            let black = [0, 2, 5, 8, 12, 16, 255];
+            for (i, p) in img.iter().enumerate() {
+                if black.contains(&i) {
+                    assert!(p < &half::f16::from_f32_const(0.001));
+                } else {
+                    assert!(p == &half::f16::from_f32_const(1.0));
+                }
+            }
+        } else {
+            panic!("Wrong data type");
+        }
+    }
+}
+
+/// Test several random images
+/// we'rell compare against a pnm file, that scales from 0 (for 0.0) to 65767 (for 1.0)
+#[test]
+fn test_predictor_ieee_fp16() {
+    // first parse pnm, skip the first 4 \n
+    let pnm_path = PathBuf::from(TEST_IMAGE_DIR).join("random-fp16.pgm");
+    let pnm_bytes = std::fs::read(pnm_path).expect("Failed to read expected PNM file");
+
+    // PGM looks like this:
+    // ---
+    // P5
+    // #Created with GIMP
+    // 16 16
+    // 65535
+    // ... <big-endian bytes>
+    // ---
+    // get index of 4th \n
+    let byte_start = pnm_bytes
+        .iter()
+        .enumerate()
+        .filter(|(_, &v)| v == b'\n')
+        .map(|(i, _)| i)
+        .nth(3)
+        .expect("Must be 4 \\n's");
+
+    let pnm_values: Vec<f32> = pnm_bytes[(byte_start + 1)..]
+        .chunks(2)
+        .map(|slice| {
+            let bts = [slice[0], slice[1]];
+            (u16::from_be_bytes(bts) as f32) / (u16::MAX as f32)
+        })
+        .collect();
+    assert!(pnm_values.len() == 256);
+
+    let filenames = [
+        "random-fp16-pred2.tiff",
+        "random-fp16-pred3.tiff",
+        "random-fp16.tiff",
+    ];
+
+    for filename in filenames.iter() {
+        let path = PathBuf::from(TEST_IMAGE_DIR).join(filename);
+        let img_file = File::open(path).expect("Cannot find test image!");
+        let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
+        assert_eq!(
+            decoder.dimensions().expect("Cannot get dimensions"),
+            (16, 16)
+        );
+        assert_eq!(
+            decoder.colortype().expect("Cannot get colortype"),
+            ColorType::Gray(16)
+        );
+        if let DecodingResult::F16(img) = decoder.read_image().unwrap() {
+            for (exp, found) in std::iter::zip(pnm_values.iter(), img.iter()) {
+                assert!((exp - found.to_f32()).abs() < 0.0001);
+            }
+        } else {
+            panic!("Wrong data type");
+        }
+    }
+}

tests/decode_geotiff_images.rs

@@ -0,0 +1,63 @@
+extern crate tiff;
+
+use tiff::decoder::{Decoder, DecodingResult};
+use tiff::tags::Tag;
+use tiff::ColorType;
+
+use std::fs::File;
+use std::path::PathBuf;
+
+const TEST_IMAGE_DIR: &str = "./tests/images";
+
+#[test]
+fn test_geo_tiff() {
+    let filenames = ["geo-5b.tif"];
+    for filename in filenames.iter() {
+        let path = PathBuf::from(TEST_IMAGE_DIR).join(filename);
+        let img_file = File::open(path).expect("Cannot find test image!");
+        let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
+        decoder = decoder.with_limits(tiff::decoder::Limits::unlimited());
+
+        assert_eq!(
+            decoder.dimensions().expect("Cannot get dimensions"),
+            (10, 10)
+        );
+        assert_eq!(
+            decoder.colortype().expect("Cannot get colortype"),
+            ColorType::Multiband {
+                bit_depth: 16,
+                num_samples: 5
+            }
+        );
+        assert_eq!(
+            decoder
+                .get_tag_u64(Tag::StripOffsets)
+                .expect("Cannot get StripOffsets"),
+            418
+        );
+        assert_eq!(
+            decoder
+                .get_tag_u64(Tag::RowsPerStrip)
+                .expect("Cannot get RowsPerStrip"),
+            10
+        );
+        assert_eq!(
+            decoder
+                .get_tag_u64(Tag::StripByteCounts)
+                .expect("Cannot get StripByteCounts"),
+            1000
+        );
+        assert_eq!(
+            decoder
+                .get_tag(Tag::ModelPixelScaleTag)
+                .expect("Cannot get pixel scale")
+                .into_f64_vec()
+                .expect("Cannot get pixel scale"),
+            vec![60.0, 60.0, 0.0]
+        );
+        let DecodingResult::I16(data) = decoder.read_image().unwrap() else {
+            panic!("Cannot read band data")
+        };
+        assert_eq!(data.len(), 500);
+    }
+}

tests/decode_images.rs

@@ -4,99 +4,173 @@ use tiff::decoder::{ifd, Decoder, DecodingResult};
 use tiff::ColorType;
 
 use std::fs::File;
+use std::path::PathBuf;
 
-#[test]
-fn test_gray_u8() {
-    let img_file =
-        File::open("./tests/images/minisblack-1c-8b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::Gray(8));
-    let img_res = decoder.read_image().unwrap();
-    if let DecodingResult::U8(res) = img_res {
-        let mut res_sum: u64 = 0;
-        for x in res {
-            res_sum += x as u64;
+const TEST_IMAGE_DIR: &str = "./tests/images/";
+
+macro_rules! test_image_sum {
+    ($name:ident, $buffer:ident, $sum_ty:ty) => {
+        fn $name(file: &str, expected_type: ColorType, expected_sum: $sum_ty) {
+            let path = PathBuf::from(TEST_IMAGE_DIR).join(file);
+            let img_file = File::open(path).expect("Cannot find test image!");
+            let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
+            assert_eq!(decoder.colortype().unwrap(), expected_type);
+            let img_res = decoder.read_image().unwrap();
+
+            match img_res {
+                DecodingResult::$buffer(res) => {
+                    let sum: $sum_ty = res.into_iter().map(<$sum_ty>::from).sum();
+                    assert_eq!(sum, expected_sum);
+                }
+                _ => panic!("Wrong bit depth"),
+            }
         }
+    };
+}
 
-        assert_eq!(res_sum, 2840893);
-    }
-    else {
-        panic!("Wrong bit depth")
-    }
+test_image_sum!(test_image_sum_u8, U8, u64);
+test_image_sum!(test_image_sum_i8, I8, i64);
+test_image_sum!(test_image_sum_u16, U16, u64);
+test_image_sum!(test_image_sum_i16, I16, i64);
+test_image_sum!(test_image_sum_u32, U32, u64);
+test_image_sum!(test_image_sum_u64, U64, u64);
+test_image_sum!(test_image_sum_f32, F32, f32);
+test_image_sum!(test_image_sum_f64, F64, f64);
+
+/// Tests that a decoder can be constructed for an image and the color type
+/// read from the IFD and is of the appropriate type, but the type is
+/// unsupported.
+fn test_image_color_type_unsupported(file: &str, expected_type: ColorType) {
+    let path = PathBuf::from(TEST_IMAGE_DIR).join(file);
+    let img_file = File::open(path).expect("Cannot find test image!");
+    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
+    assert_eq!(decoder.colortype().unwrap(), expected_type);
+    assert!(match decoder.read_image() {
+        Err(tiff::TiffError::UnsupportedError(
+            tiff::TiffUnsupportedError::UnsupportedColorType(_),
+        )) => true,
+        _ => false,
+    });
 }
 
 #[test]
-fn test_rgb_u8() {
-    let img_file = File::open("./tests/images/rgb-3c-8b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::RGB(8));
-    let img_res = decoder.read_image().unwrap();
-    if let DecodingResult::U8(res) = img_res {
-        let mut res_sum: u64 = 0;
-        for x in res {
-            res_sum += x as u64;
-        }
+fn test_cmyk_u8() {
+    test_image_sum_u8("cmyk-3c-8b.tiff", ColorType::CMYK(8), 8522658);
+}
 
-        assert_eq!(res_sum, 7842108)
-    }
-    else {
-        panic!("Wrong bit depth")
-    }
+#[test]
+fn test_cmyk_u16() {
+    test_image_sum_u16("cmyk-3c-16b.tiff", ColorType::CMYK(16), 2181426827);
+}
+
+#[test]
+fn test_cmyk_f32() {
+    test_image_sum_f32("cmyk-3c-32b-float.tiff", ColorType::CMYK(32), 496.0405);
+}
+
+#[test]
+fn test_gray_u8() {
+    test_image_sum_u8("minisblack-1c-8b.tiff", ColorType::Gray(8), 2840893);
+}
+
+#[test]
+fn test_gray_u12() {
+    test_image_color_type_unsupported("12bit.cropped.tiff", ColorType::Gray(12));
 }
 
 #[test]
 fn test_gray_u16() {
-    let img_file =
-        File::open("./tests/images/minisblack-1c-16b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::Gray(16));
-    let img_res = decoder.read_image().unwrap();
-    if let DecodingResult::U16(res) = img_res {
-        let mut res_sum: u64 = 0;
-        for x in res {
-            res_sum += x as u64;
-        }
+    test_image_sum_u16("minisblack-1c-16b.tiff", ColorType::Gray(16), 733126239);
+}
 
-        assert_eq!(res_sum, 733126239);
-    }
-    else {
-        panic!("Wrong bit depth")
-    }
+#[test]
+fn test_gray_u32() {
+    test_image_sum_u32("gradient-1c-32b.tiff", ColorType::Gray(32), 549892913787);
+}
+
+#[test]
+fn test_gray_u64() {
+    test_image_sum_u64("gradient-1c-64b.tiff", ColorType::Gray(64), 549892913787);
+}
+
+#[test]
+fn test_gray_f32() {
+    test_image_sum_f32("gradient-1c-32b-float.tiff", ColorType::Gray(32), 128.03194);
+}
+
+#[test]
+fn test_gray_f64() {
+    test_image_sum_f64(
+        "gradient-1c-64b-float.tiff",
+        ColorType::Gray(64),
+        128.0319210877642,
+    );
+}
+
+#[test]
+fn test_rgb_u8() {
+    test_image_sum_u8("rgb-3c-8b.tiff", ColorType::RGB(8), 7842108);
+}
+
+#[test]
+fn test_rgb_u12() {
+    test_image_color_type_unsupported("12bit.cropped.rgb.tiff", ColorType::RGB(12));
 }
 
 #[test]
 fn test_rgb_u16() {
-    let img_file = File::open("./tests/images/rgb-3c-16b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::RGB(16));
-    let img_res = decoder.read_image().unwrap();
-    if let DecodingResult::U16(res) = img_res {
-        let mut res_sum: u64 = 0;
-        for x in res {
-            res_sum += x as u64;
-        }
+    test_image_sum_u16("rgb-3c-16b.tiff", ColorType::RGB(16), 2024349944);
+}
 
-        assert_eq!(res_sum, 2024349944);
-    }
-    else {
-        panic!("Wrong bit depth")
-    }
+#[test]
+fn test_rgb_u32() {
+    test_image_sum_u32("gradient-3c-32b.tiff", ColorType::RGB(32), 2030834111716);
+}
+
+#[test]
+fn test_rgb_u64() {
+    test_image_sum_u64("gradient-3c-64b.tiff", ColorType::RGB(64), 2030834111716);
+}
+
+#[test]
+fn test_rgb_f32() {
+    test_image_sum_f32("gradient-3c-32b-float.tiff", ColorType::RGB(32), 472.8405);
+}
+
+#[test]
+fn test_int8() {
+    test_image_sum_i8("int8.tif", ColorType::Gray(8), 3111)
+}
+
+#[test]
+fn test_int8_rgb() {
+    test_image_sum_i8("int8_rgb.tif", ColorType::RGB(8), -10344)
+}
+
+#[test]
+fn test_int16() {
+    test_image_sum_i16("int16.tif", ColorType::Gray(16), 354396);
+}
+
+#[test]
+fn test_int16_rgb() {
+    test_image_sum_i16("int16_rgb.tif", ColorType::RGB(16), 1063188);
 }
 
 #[test]
 fn test_string_tags() {
     // these files have null-terminated strings for their Software tag. One has extra bytes after
     // the null byte, so we check both to ensure that we're truncating properly
-    let filenames = vec!["minisblack-1c-16b.tiff", "rgb-3c-16b.tiff"];
+    let filenames = ["minisblack-1c-16b.tiff", "rgb-3c-16b.tiff"];
     for filename in filenames.iter() {
-        let path = format!("./tests/images/{}", filename);
-        let img_file = File::open(path).expect("can't open file");
+        let path = PathBuf::from(TEST_IMAGE_DIR).join(filename);
+        let img_file = File::open(path).expect("Cannot find test image!");
         let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-        let software = decoder.get_tag(ifd::Tag::Software).unwrap();
+        let software = decoder.get_tag(tiff::tags::Tag::Software).unwrap();
         match software {
             ifd::Value::Ascii(s) => assert_eq!(
-                s,
-                String::from("GraphicsMagick 1.2 unreleased Q16 http://www.GraphicsMagick.org/")
+                &s,
+                "GraphicsMagick 1.2 unreleased Q16 http://www.GraphicsMagick.org/"
             ),
             _ => assert!(false),
         };
@@ -125,6 +199,12 @@ fn test_decode_data() {
     }
 }
 
+#[test]
+fn issue_69() {
+    test_image_sum_u16("issue_69_lzw.tiff", ColorType::Gray(16), 1015486);
+    test_image_sum_u16("issue_69_packbits.tiff", ColorType::Gray(16), 1015486);
+}
+
 // TODO: GrayA support
 //#[test]
 //fn test_gray_alpha_u8()
@@ -135,3 +215,310 @@ fn test_decode_data() {
 //let img_res = decoder.read_image();
 //assert!(img_res.is_ok());
 //}
+
+#[test]
+fn test_tiled_gray_i1() {
+    test_image_sum_u8("tiled-gray-i1.tif", ColorType::Gray(1), 30531);
+}
+
+#[test]
+fn test_tiled_rgb_u8() {
+    test_image_sum_u8("tiled-rgb-u8.tif", ColorType::RGB(8), 39528948);
+}
+
+#[test]
+fn test_tiled_rect_rgb_u8() {
+    test_image_sum_u8("tiled-rect-rgb-u8.tif", ColorType::RGB(8), 62081032);
+}
+
+/* #[test]
+fn test_tiled_jpeg_rgb_u8() {
+    test_image_sum_u8("tiled-jpeg-rgb-u8.tif", ColorType::RGB(8), 93031606);
+} */
+
+#[test]
+fn test_tiled_oversize_gray_i8() {
+    test_image_sum_i8("tiled-oversize-gray-i8.tif", ColorType::Gray(8), 1214996);
+}
+
+#[test]
+fn test_tiled_cmyk_i8() {
+    test_image_sum_i8("tiled-cmyk-i8.tif", ColorType::CMYK(8), 1759101);
+}
+
+#[test]
+fn test_tiled_incremental() {
+    let file = "tiled-rgb-u8.tif";
+    let expected_type = ColorType::RGB(8);
+    let sums = [
+        188760, 195639, 108148, 81986, 665088, 366140, 705317, 423366, 172033, 324455, 244102,
+        81853, 181258, 247971, 129486, 55600, 565625, 422102, 730888, 379271, 232142, 292549,
+        244045, 86866, 188141, 115036, 150785, 84389, 353170, 459325, 719619, 329594, 278663,
+        220474, 243048, 113563, 189152, 109684, 179391, 122188, 279651, 622093, 724682, 302459,
+        268428, 204499, 224255, 124674, 170668, 121868, 192768, 183367, 378029, 585651, 657712,
+        296790, 241444, 197083, 198429, 134869, 182318, 86034, 203655, 182338, 297255, 601284,
+        633813, 242531, 228578, 206441, 193552, 125412, 181527, 165439, 202531, 159538, 268388,
+        565790, 611382, 272967, 236497, 215154, 158881, 90806, 106114, 182342, 191824, 186138,
+        215174, 393193, 701228, 198866, 227944, 193830, 166330, 49008, 55719, 122820, 197316,
+        161969, 203152, 170986, 624427, 188605, 186187, 111064, 115192, 39538, 48626, 163929,
+        144682, 135796, 194141, 154198, 584125, 180255, 153524, 121433, 132641, 35743, 47798,
+        152343, 162874, 167664, 160175, 133038, 659882, 138339, 166470, 124173, 118929, 51317,
+        45267, 155776, 161331, 161006, 130052, 137618, 337291, 106481, 161999, 127343, 87724,
+        59540, 63907, 155677, 140668, 141523, 108061, 168657, 186482, 98599, 147614, 139963, 90444,
+        56602, 92547, 125644, 134212, 126569, 144153, 179800, 174516, 133969, 129399, 117681,
+        83305, 55075, 110737, 115108, 128572, 128911, 130922, 179986, 143288, 145884, 155856,
+        96683, 94057, 56238, 79649, 71651, 70182, 75010, 77009, 98855, 78979, 74341, 83482, 53403,
+        59842, 30305,
+    ];
+
+    let path = PathBuf::from(TEST_IMAGE_DIR).join(file);
+    let img_file = File::open(path).expect("Cannot find test image!");
+    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
+    assert_eq!(decoder.colortype().unwrap(), expected_type);
+
+    let tiles = decoder.tile_count().unwrap();
+    assert_eq!(tiles as usize, sums.len());
+
+    for tile in 0..tiles {
+        match decoder.read_chunk(tile).unwrap() {
+            DecodingResult::U8(res) => {
+                let sum: u64 = res.into_iter().map(<u64>::from).sum();
+                assert_eq!(sum, sums[tile as usize]);
+            }
+            _ => panic!("Wrong bit depth"),
+        }
+    }
+}
+
+#[test]
+fn test_planar_rgb_u8() {
+    // gdal_translate tiled-rgb-u8.tif planar-rgb-u8.tif -co INTERLEAVE=BAND -co COMPRESS=LZW -co PROFILE=BASELINE
+    let file = "planar-rgb-u8.tif";
+    let expected_type = ColorType::RGB(8);
+
+    let path = PathBuf::from(TEST_IMAGE_DIR).join(file);
+    let img_file = File::open(path).expect("Cannot find test image!");
+    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
+    assert_eq!(decoder.colortype().unwrap(), expected_type);
+
+    let chunks = decoder.strip_count().unwrap();
+    assert_eq!(chunks as usize, 72);
+
+    // convert -quiet planar-rgb-u8.tif[0] -crop 1x1+0+0 txt:
+    // 0,0: (73,51,30)  #49331E  srgb(73,51,30)
+
+    // 1st band (red)
+    match decoder.read_chunk(0).unwrap() {
+        DecodingResult::U8(chunk) => {
+            assert_eq!(chunk[0], 73);
+        }
+        _ => panic!("Wrong bit depth"),
+    }
+    // 2nd band (green)
+    match decoder.read_chunk(chunks / 3).unwrap() {
+        DecodingResult::U8(chunk) => {
+            assert_eq!(chunk[0], 51);
+        }
+        _ => panic!("Wrong bit depth"),
+    }
+    // 3rd band (blue)
+    match decoder.read_chunk(chunks / 3 * 2).unwrap() {
+        DecodingResult::U8(chunk) => {
+            assert_eq!(chunk[0], 30);
+        }
+        _ => panic!("Wrong bit depth"),
+    }
+
+    test_image_sum_u8(file, ColorType::RGB(8), 15417630);
+}
+
+#[test]
+fn test_div_zero() {
+    use tiff::{TiffError, TiffFormatError};
+
+    let image = [
+        73, 73, 42, 0, 8, 0, 0, 0, 8, 0, 0, 1, 4, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 40, 1, 0, 0,
+        0, 158, 0, 0, 251, 3, 1, 3, 0, 1, 0, 0, 0, 1, 0, 0, 39, 6, 1, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0,
+        17, 1, 4, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 3, 0, 1, 0, 0, 0, 158, 0, 0, 251, 67, 1, 3, 0,
+        1, 0, 0, 0, 40, 0, 0, 0, 66, 1, 4, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 48, 178, 178, 178, 178,
+        178, 178, 178,
+    ];
+
+    let err = tiff::decoder::Decoder::new(std::io::Cursor::new(&image)).unwrap_err();
+
+    match err {
+        TiffError::FormatError(TiffFormatError::StripTileTagConflict) => {}
+        unexpected => panic!("Unexpected error {}", unexpected),
+    }
+}
+
+#[test]
+fn test_too_many_value_bytes() {
+    let image = [
+        73, 73, 43, 0, 8, 0, 0, 0, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255, 0, 8, 0, 0, 0,
+        23, 0, 12, 0, 0, 65, 4, 0, 1, 6, 0, 0, 1, 16, 0, 1, 0, 0, 0, 0, 0, 0, 128, 0, 0, 0, 0, 0,
+        0, 0, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0, 59, 73, 84, 186, 202, 83, 240, 66, 1, 53, 22, 56, 47,
+        0, 0, 0, 0, 0, 0, 1, 222, 4, 0, 58, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 4, 0, 0, 100, 0,
+        0, 89, 89, 89, 89, 89, 89, 89, 89, 96, 1, 20, 89, 89, 89, 89, 18,
+    ];
+
+    let error = tiff::decoder::Decoder::new(std::io::Cursor::new(&image)).unwrap_err();
+
+    match error {
+        tiff::TiffError::LimitsExceeded => {}
+        unexpected => panic!("Unexpected error {}", unexpected),
+    }
+}
+
+#[test]
+fn fuzzer_testcase5() {
+    let image = [
+        73, 73, 42, 0, 8, 0, 0, 0, 8, 0, 0, 1, 4, 0, 1, 0, 0, 0, 100, 0, 0, 0, 1, 1, 4, 0, 1, 0, 0,
+        0, 158, 0, 0, 251, 3, 1, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0, 6, 1, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0,
+        17, 1, 4, 0, 1, 0, 0, 0, 0, 0, 0, 0, 2, 1, 3, 0, 0, 0, 0, 0, 246, 16, 0, 0, 22, 1, 4, 0, 1,
+        0, 0, 0, 40, 0, 251, 255, 23, 1, 4, 0, 1, 0, 0, 0, 48, 178, 178, 178, 178, 178, 178, 178,
+        178, 178, 178,
+    ];
+
+    let _ = tiff::decoder::Decoder::new(std::io::Cursor::new(&image)).unwrap_err();
+}
+
+#[test]
+fn fuzzer_testcase1() {
+    let image = [
+        73, 73, 42, 0, 8, 0, 0, 0, 8, 0, 0, 1, 4, 0, 1, 0, 0, 0, 99, 255, 255, 254, 1, 1, 4, 0, 1,
+        0, 0, 0, 158, 0, 0, 251, 3, 1, 3, 255, 254, 255, 255, 0, 1, 0, 0, 0, 6, 1, 3, 0, 1, 0, 0,
+        0, 0, 0, 0, 0, 17, 1, 4, 0, 9, 0, 0, 0, 0, 0, 0, 0, 2, 1, 3, 0, 2, 0, 0, 0, 63, 0, 0, 0,
+        22, 1, 4, 0, 1, 0, 0, 0, 44, 0, 0, 0, 23, 1, 4, 0, 0, 0, 0, 0, 0, 0, 2, 1, 3, 1, 0, 178,
+        178,
+    ];
+
+    let _ = tiff::decoder::Decoder::new(std::io::Cursor::new(&image)).unwrap_err();
+}
+
+#[test]
+fn fuzzer_testcase6() {
+    let image = [
+        73, 73, 42, 0, 8, 0, 0, 0, 8, 0, 0, 1, 4, 0, 1, 0, 0, 0, 100, 0, 0, 148, 1, 1, 4, 0, 1, 0,
+        0, 0, 158, 0, 0, 251, 3, 1, 3, 255, 254, 255, 255, 0, 1, 0, 0, 0, 6, 1, 3, 0, 1, 0, 0, 0,
+        0, 0, 0, 0, 17, 1, 4, 0, 1, 0, 0, 0, 0, 0, 0, 0, 2, 1, 3, 0, 2, 0, 0, 0, 63, 0, 0, 0, 22,
+        1, 4, 0, 1, 0, 0, 0, 44, 0, 248, 255, 23, 1, 4, 0, 1, 0, 0, 0, 178, 178, 178, 0, 1, 178,
+        178, 178,
+    ];
+
+    let _ = tiff::decoder::Decoder::new(std::io::Cursor::new(&image)).unwrap_err();
+}
+
+#[test]
+fn oom() {
+    let image = [
+        73, 73, 42, 0, 8, 0, 0, 0, 8, 0, 0, 1, 4, 0, 1, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 40, 1, 0, 0,
+        0, 158, 0, 0, 251, 3, 1, 3, 0, 1, 0, 0, 0, 7, 0, 0, 0, 6, 1, 3, 0, 1, 0, 0, 0, 2, 0, 0, 0,
+        17, 1, 4, 0, 1, 0, 0, 0, 3, 77, 0, 0, 1, 1, 3, 0, 1, 0, 0, 0, 3, 128, 0, 0, 22, 1, 4, 0, 1,
+        0, 0, 0, 40, 0, 0, 0, 23, 1, 4, 0, 1, 0, 0, 0, 178, 48, 178, 178, 178, 178, 162, 178,
+    ];
+
+    let _ = tiff::decoder::Decoder::new(std::io::Cursor::new(&image)).unwrap_err();
+}
+
+#[test]
+fn fuzzer_testcase4() {
+    let image = [
+        73, 73, 42, 0, 8, 0, 0, 0, 8, 0, 0, 1, 4, 0, 1, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 40, 1, 0, 0,
+        0, 158, 0, 0, 251, 3, 1, 3, 0, 1, 0, 0, 0, 5, 0, 0, 0, 6, 1, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0,
+        17, 1, 4, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 3, 0, 1, 0, 0, 0, 3, 128, 0, 0, 22, 1, 4, 0, 1,
+        0, 0, 0, 40, 0, 0, 0, 23, 1, 4, 0, 1, 0, 0, 0, 48, 178, 178, 178, 0, 1, 0, 13, 13,
+    ];
+
+    let _ = tiff::decoder::Decoder::new(std::io::Cursor::new(&image)).unwrap_err();
+}
+
+#[test]
+fn fuzzer_testcase2() {
+    let image = [
+        73, 73, 42, 0, 8, 0, 0, 0, 15, 0, 0, 254, 44, 1, 0, 0, 0, 0, 0, 32, 0, 0, 0, 1, 4, 0, 1, 0,
+        0, 0, 0, 1, 0, 0, 91, 1, 1, 0, 0, 0, 0, 0, 242, 4, 0, 0, 0, 22, 0, 56, 77, 0, 77, 1, 0, 0,
+        73, 42, 0, 1, 4, 0, 1, 0, 0, 0, 4, 0, 8, 0, 0, 1, 4, 0, 1, 0, 0, 0, 158, 0, 0, 251, 3, 1,
+        3, 0, 1, 0, 0, 0, 7, 0, 0, 0, 6, 1, 3, 0, 1, 0, 0, 0, 2, 0, 0, 0, 17, 1, 4, 0, 1, 0, 0, 0,
+        0, 0, 0, 0, 1, 1, 3, 0, 1, 0, 0, 0, 0, 0, 0, 4, 61, 1, 18, 0, 1, 0, 0, 0, 202, 0, 0, 0, 17,
+        1, 100, 0, 129, 0, 0, 0, 0, 0, 0, 0, 232, 254, 252, 255, 254, 255, 255, 255, 1, 29, 0, 0,
+        22, 1, 3, 0, 1, 0, 0, 0, 16, 0, 0, 0, 23, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 123, 73, 254, 0,
+        73,
+    ];
+
+    let _ = tiff::decoder::Decoder::new(std::io::Cursor::new(&image)).unwrap_err();
+}
+
+#[test]
+fn invalid_jpeg_tag_2() {
+    let image = [
+        73, 73, 42, 0, 8, 0, 0, 0, 16, 0, 254, 0, 4, 0, 1, 0, 0, 0, 0, 0, 0, 242, 0, 1, 4, 0, 1, 0,
+        0, 0, 0, 129, 16, 0, 1, 1, 4, 0, 1, 0, 0, 0, 214, 0, 0, 248, 253, 1, 3, 0, 1, 0, 0, 0, 64,
+        0, 0, 0, 3, 1, 3, 0, 1, 0, 0, 0, 7, 0, 0, 0, 6, 1, 3, 0, 1, 0, 0, 0, 1, 0, 0, 64, 14, 1, 0,
+        2, 0, 0, 148, 0, 206, 0, 0, 0, 17, 1, 4, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0,
+        1, 0, 0, 0, 22, 1, 4, 0, 17, 0, 0, 201, 1, 0, 0, 0, 23, 1, 2, 0, 20, 0, 0, 0, 194, 0, 0, 0,
+        91, 1, 7, 0, 5, 0, 0, 0, 64, 0, 0, 0, 237, 254, 65, 255, 255, 255, 255, 255, 1, 0, 0, 0,
+        22, 1, 4, 0, 1, 0, 0, 0, 42, 0, 0, 0, 23, 1, 255, 255, 255, 255, 255, 36, 36, 0, 0, 0, 0,
+        0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 36, 73, 73, 0, 42, 36, 36, 36, 36, 0, 0, 8, 0,
+    ];
+
+    let _ = tiff::decoder::Decoder::new(std::io::Cursor::new(&image)).unwrap_err();
+}
+
+#[test]
+fn fuzzer_testcase3() {
+    let image = [
+        73, 73, 42, 0, 8, 0, 0, 0, 8, 0, 0, 1, 4, 0, 1, 0, 0, 0, 2, 0, 0, 0, 61, 1, 9, 0, 46, 22,
+        128, 0, 0, 0, 0, 1, 6, 1, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0, 17, 1, 4, 0, 27, 0, 0, 0, 0, 0, 0,
+        0, 1, 1, 3, 0, 1, 0, 0, 0, 17, 1, 0, 231, 22, 1, 1, 0, 1, 0, 0, 0, 130, 0, 0, 0, 23, 1, 4,
+        0, 14, 0, 0, 0, 0, 0, 0, 0, 133, 133, 133, 77, 77, 77, 0, 0, 22, 128, 0, 255, 255, 255,
+        255, 255,
+    ];
+
+    let _ = tiff::decoder::Decoder::new(std::io::Cursor::new(&image)).unwrap_err();
+}
+
+#[test]
+fn timeout() {
+    use tiff::{TiffError, TiffFormatError};
+
+    let image = [
+        73, 73, 42, 0, 8, 0, 0, 0, 16, 0, 254, 0, 4, 0, 1, 68, 0, 0, 0, 2, 0, 32, 254, 252, 0, 109,
+        0, 129, 0, 0, 0, 32, 0, 58, 0, 1, 4, 0, 1, 0, 6, 0, 0, 0, 8, 0, 0, 1, 73, 73, 42, 0, 8, 0,
+        0, 0, 8, 0, 0, 1, 4, 0, 1, 0, 0, 0, 21, 0, 0, 0, 61, 1, 255, 128, 9, 0, 0, 8, 0, 1, 113, 2,
+        3, 1, 3, 0, 1, 0, 0, 0, 5, 0, 65, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 112, 0, 0, 36, 0, 0,
+        0, 112, 56, 200, 0, 5, 0, 0, 64, 0, 0, 1, 0, 4, 0, 0, 0, 2, 0, 6, 1, 3, 0, 1, 0, 0, 0, 0,
+        0, 0, 4, 17, 1, 1, 0, 93, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1, 0, 0, 0, 3, 6, 0, 231, 22, 1,
+        1, 0, 1, 0, 0, 0, 2, 64, 118, 36, 23, 1, 1, 0, 43, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 4, 0, 8,
+        0, 0, 73, 73, 42, 0, 8, 0, 0, 0, 0, 0, 32,
+    ];
+
+    let error = tiff::decoder::Decoder::new(std::io::Cursor::new(&image)).unwrap_err();
+
+    match error {
+        TiffError::FormatError(TiffFormatError::CycleInOffsets) => {}
+        e => panic!("Unexpected error {:?}", e),
+    }
+}
+
+#[test]
+fn test_no_rows_per_strip() {
+    test_image_sum_u8("no_rows_per_strip.tiff", ColorType::RGB(8), 99448840);
+}
+
+#[test]
+fn test_predictor_3_rgb_f32() {
+    test_image_sum_f32("predictor-3-rgb-f32.tif", ColorType::RGB(32), 54004.33);
+}
+
+#[test]
+fn test_predictor_3_gray_f32() {
+    test_image_sum_f32("predictor-3-gray-f32.tif", ColorType::Gray(32), 20008.275);
+}
+
+#[test]
+#[cfg(feature = "zstd")]
+fn test_zstd_compression() {
+    // gdal_translate -co COMPRESS=ZSTD -co ZSTD_LEVEL=20 int16.tif int16_zstd.tif
+    test_image_sum_i16("int16_zstd.tif", ColorType::Gray(16), 354396);
+}

tests/encode_images.rs

@@ -1,13 +1,13 @@
-extern crate tempfile;
 extern crate tiff;
 
-use tiff::decoder::{Decoder, DecodingResult};
-use tiff::decoder::ifd::Tag;
-use tiff::encoder::{colortype, TiffEncoder, SRational};
+use tiff::decoder::{ifd, Decoder, DecodingResult};
+use tiff::encoder::{colortype, Ifd, Ifd8, SRational, TiffEncoder};
+use tiff::tags::Tag;
 use tiff::ColorType;
 
 use std::fs::File;
 use std::io::{Cursor, Seek, SeekFrom};
+use std::path::PathBuf;
 
 #[test]
 fn encode_decode() {
@@ -20,18 +20,67 @@ fn encode_decode() {
             image_data.push(val);
         }
     }
-    let mut file = tempfile::tempfile().unwrap();
+    let mut file = Cursor::new(Vec::new());
     {
         let mut tiff = TiffEncoder::new(&mut file).unwrap();
 
-        tiff.write_image::<colortype::RGB8>(100, 100, &image_data)
+        let mut image = tiff.new_image::<colortype::RGB8>(100, 100).unwrap();
+        image
+            .encoder()
+            .write_tag(Tag::Artist, "Image-tiff")
             .unwrap();
+        image.write_data(&image_data).unwrap();
     }
     {
         file.seek(SeekFrom::Start(0)).unwrap();
         let mut decoder = Decoder::new(&mut file).unwrap();
         assert_eq!(decoder.colortype().unwrap(), ColorType::RGB(8));
         assert_eq!(decoder.dimensions().unwrap(), (100, 100));
+
+        let mut all_tags = decoder
+            .tag_iter()
+            .filter_map(Result::ok)
+            .collect::<Vec<_>>();
+        all_tags.sort_by_key(|(t, _)| t.to_u16());
+        assert_eq!(
+            all_tags,
+            vec![
+                (Tag::ImageWidth, ifd::Value::Unsigned(100)),
+                (Tag::ImageLength, ifd::Value::Unsigned(100)),
+                (
+                    Tag::BitsPerSample,
+                    ifd::Value::List(vec![
+                        ifd::Value::Short(8),
+                        ifd::Value::Short(8),
+                        ifd::Value::Short(8)
+                    ])
+                ),
+                (Tag::Compression, ifd::Value::Short(1)),
+                (Tag::PhotometricInterpretation, ifd::Value::Short(2)),
+                (Tag::StripOffsets, ifd::Value::Unsigned(47)),
+                (Tag::SamplesPerPixel, ifd::Value::Short(3)),
+                (Tag::RowsPerStrip, ifd::Value::Unsigned(3334)),
+                (Tag::StripByteCounts, ifd::Value::Unsigned(30000)),
+                (Tag::XResolution, ifd::Value::Rational(1, 1)),
+                (Tag::YResolution, ifd::Value::Rational(1, 1)),
+                (Tag::ResolutionUnit, ifd::Value::Short(1)),
+                (Tag::Artist, ifd::Value::Ascii("Image-tiff".into())),
+                (Tag::Predictor, ifd::Value::Short(1)),
+                (
+                    Tag::SampleFormat,
+                    ifd::Value::List(vec![
+                        ifd::Value::Short(1),
+                        ifd::Value::Short(1),
+                        ifd::Value::Short(1)
+                    ])
+                ),
+            ]
+        );
+
+        assert_eq!(
+            decoder.get_tag(Tag::Artist).unwrap(),
+            ifd::Value::Ascii("Image-tiff".into())
+        );
         if let DecodingResult::U8(img_res) = decoder.read_image().unwrap() {
             assert_eq!(image_data, img_res);
         } else {
@@ -40,6 +89,134 @@ fn encode_decode() {
     }
 }
 
+#[test]
+fn encode_decode_big() {
+    let mut image_data = Vec::new();
+    for x in 0..100 {
+        for y in 0..100u8 {
+            let val = x + y;
+            image_data.push(val);
+            image_data.push(val);
+            image_data.push(val);
+        }
+    }
+    let mut file = Cursor::new(Vec::new());
+    {
+        let mut tiff = TiffEncoder::new_big(&mut file).unwrap();
+
+        let mut image = tiff.new_image::<colortype::RGB8>(100, 100).unwrap();
+        image
+            .encoder()
+            .write_tag(Tag::Artist, "Image-tiff")
+            .unwrap();
+        image.write_data(&image_data).unwrap();
+    }
+    {
+        file.seek(SeekFrom::Start(0)).unwrap();
+        let mut decoder = Decoder::new(&mut file).unwrap();
+        assert_eq!(decoder.colortype().unwrap(), ColorType::RGB(8));
+        assert_eq!(decoder.dimensions().unwrap(), (100, 100));
+
+        let mut all_tags = decoder
+            .tag_iter()
+            .filter_map(Result::ok)
+            .collect::<Vec<_>>();
+        all_tags.sort_by_key(|(t, _)| t.to_u16());
+        assert_eq!(
+            all_tags,
+            vec![
+                (Tag::ImageWidth, ifd::Value::Unsigned(100)),
+                (Tag::ImageLength, ifd::Value::Unsigned(100)),
+                (
+                    Tag::BitsPerSample,
+                    ifd::Value::List(vec![
+                        ifd::Value::Short(8),
+                        ifd::Value::Short(8),
+                        ifd::Value::Short(8)
+                    ])
+                ),
+                (Tag::Compression, ifd::Value::Short(1)),
+                (Tag::PhotometricInterpretation, ifd::Value::Short(2)),
+                (Tag::StripOffsets, ifd::Value::UnsignedBig(27)),
+                (Tag::SamplesPerPixel, ifd::Value::Short(3)),
+                (Tag::RowsPerStrip, ifd::Value::Unsigned(3334)),
+                (Tag::StripByteCounts, ifd::Value::UnsignedBig(30000)),
+                (Tag::XResolution, ifd::Value::Rational(1, 1)),
+                (Tag::YResolution, ifd::Value::Rational(1, 1)),
+                (Tag::ResolutionUnit, ifd::Value::Short(1)),
+                (Tag::Artist, ifd::Value::Ascii("Image-tiff".into())),
+                (Tag::Predictor, ifd::Value::Short(1)),
+                (
+                    Tag::SampleFormat,
+                    ifd::Value::List(vec![
+                        ifd::Value::Short(1),
+                        ifd::Value::Short(1),
+                        ifd::Value::Short(1)
+                    ])
+                ),
+            ]
+        );
+
+        assert_eq!(
+            decoder.get_tag(Tag::Artist).unwrap(),
+            ifd::Value::Ascii("Image-tiff".into())
+        );
+        if let DecodingResult::U8(img_res) = decoder.read_image().unwrap() {
+            assert_eq!(image_data, img_res);
+        } else {
+            panic!("Wrong data type");
+        }
+    }
+}
+
+#[test]
+fn test_encode_ifd() {
+    let mut data = Cursor::new(Vec::new());
+
+    {
+        let mut tiff = TiffEncoder::new(&mut data).unwrap();
+        let mut image_encoder = tiff.new_image::<colortype::Gray8>(1, 1).unwrap();
+        image_encoder.write_strip(&[1]).unwrap();
+        let encoder = image_encoder.encoder();
+
+        // Use the "reusable" tags section as per the TIFF6 spec
+        encoder.write_tag(Tag::Unknown(65000), Ifd(42u32)).unwrap();
+        encoder
+            .write_tag(Tag::Unknown(65001), &[Ifd(100u32)][..])
+            .unwrap();
+        encoder
+            .write_tag(Tag::Unknown(65002), &[Ifd(1u32), Ifd(2u32), Ifd(3u32)][..])
+            .unwrap();
+
+        encoder.write_tag(Tag::Unknown(65010), Ifd8(43u64)).unwrap();
+        encoder
+            .write_tag(Tag::Unknown(65011), &[Ifd8(100u64)][..])
+            .unwrap();
+        encoder
+            .write_tag(
+                Tag::Unknown(65012),
+                &[Ifd8(1u64), Ifd8(2u64), Ifd8(3u64)][..],
+            )
+            .unwrap();
+    }
+
+    // Rewind the cursor for reading
+    data.set_position(0);
+    {
+        let mut decoder = Decoder::new(&mut data).unwrap();
+
+        assert_eq!(decoder.assert_tag_u32(65000), 42);
+        assert_eq!(decoder.assert_tag_u32_vec(65000), [42]);
+        assert_eq!(decoder.assert_tag_u32_vec(65001), [100]);
+        assert_eq!(decoder.assert_tag_u32_vec(65002), [1, 2, 3]);
+
+        assert_eq!(decoder.assert_tag_u64(65010), 43);
+        assert_eq!(decoder.assert_tag_u64_vec(65010), [43]);
+        assert_eq!(decoder.assert_tag_u64_vec(65011), [100]);
+        assert_eq!(decoder.assert_tag_u64_vec(65012), [1, 2, 3]);
+    }
+}
+
 #[test]
 /// Test that attempting to encode when the input buffer is undersized returns
 /// an error rather than panicking.
@@ -54,126 +231,190 @@ fn test_encode_undersized_buffer() {
     }
 }
 
+const TEST_IMAGE_DIR: &str = "./tests/images/";
+
+macro_rules! test_roundtrip {
+    ($name:ident, $buffer:ident, $buffer_ty:ty) => {
+        fn $name<C: colortype::ColorType<Inner = $buffer_ty>>(
+            file: &str,
+            expected_type: ColorType,
+        ) {
+            let path = PathBuf::from(TEST_IMAGE_DIR).join(file);
+            let img_file = File::open(path).expect("Cannot find test image!");
+            let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
+            assert_eq!(decoder.colortype().unwrap(), expected_type);
+
+            let image_data = match decoder.read_image().unwrap() {
+                DecodingResult::$buffer(res) => res,
+                _ => panic!("Wrong data type"),
+            };
+
+            let mut file = Cursor::new(Vec::new());
+            {
+                let mut tiff = TiffEncoder::new(&mut file).unwrap();
+
+                let (width, height) = decoder.dimensions().unwrap();
+                tiff.write_image::<C>(width, height, &image_data).unwrap();
+            }
+            file.seek(SeekFrom::Start(0)).unwrap();
+            {
+                let mut decoder = Decoder::new(&mut file).unwrap();
+                if let DecodingResult::$buffer(img_res) = decoder.read_image().unwrap() {
+                    assert_eq!(image_data, img_res);
+                } else {
+                    panic!("Wrong data type");
+                }
+            }
+        }
+    };
+}
+
+test_roundtrip!(test_u8_roundtrip, U8, u8);
+test_roundtrip!(test_i8_roundtrip, I8, i8);
+test_roundtrip!(test_u16_roundtrip, U16, u16);
+test_roundtrip!(test_i16_roundtrip, I16, i16);
+test_roundtrip!(test_u32_roundtrip, U32, u32);
+test_roundtrip!(test_u64_roundtrip, U64, u64);
+test_roundtrip!(test_f32_roundtrip, F32, f32);
+test_roundtrip!(test_f64_roundtrip, F64, f64);
 
 #[test]
 fn test_gray_u8_roundtrip() {
-    let img_file =
-        File::open("./tests/images/minisblack-1c-8b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::Gray(8));
+    test_u8_roundtrip::<colortype::Gray8>("minisblack-1c-8b.tiff", ColorType::Gray(8));
+}
 
-    let image_data = match decoder.read_image().unwrap() {
-        DecodingResult::U8(res) => res,
-        _ => panic!("Wrong data type"),
-    };
-
-    let mut file = tempfile::tempfile().unwrap();
-    {
-        let mut tiff = TiffEncoder::new(&mut file).unwrap();
-
-        let (width, height) = decoder.dimensions().unwrap();
-        tiff.write_image::<colortype::Gray8>(width, height, &image_data)
-            .unwrap();
-    }
-    file.seek(SeekFrom::Start(0)).unwrap();
-    {
-        let mut decoder = Decoder::new(&mut file).unwrap();
-        if let DecodingResult::U8(img_res) = decoder.read_image().unwrap() {
-            assert_eq!(image_data, img_res);
-        } else {
-            panic!("Wrong data type");
-        }
-    }
+#[test]
+fn test_gray_i8_roundtrip() {
+    test_i8_roundtrip::<colortype::GrayI8>("minisblack-1c-i8b.tiff", ColorType::Gray(8));
 }
 
 #[test]
 fn test_rgb_u8_roundtrip() {
-    let img_file = File::open("./tests/images/rgb-3c-8b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::RGB(8));
+    test_u8_roundtrip::<colortype::RGB8>("rgb-3c-8b.tiff", ColorType::RGB(8));
+}
 
-    let image_data = match decoder.read_image().unwrap() {
-        DecodingResult::U8(res) => res,
-        _ => panic!("Wrong data type"),
-    };
+#[test]
+fn test_cmyk_u8_roundtrip() {
+    test_u8_roundtrip::<colortype::CMYK8>("cmyk-3c-8b.tiff", ColorType::CMYK(8));
+}
 
-    let mut file = tempfile::tempfile().unwrap();
-    {
-        let mut tiff = TiffEncoder::new(&mut file).unwrap();
-
-        let (width, height) = decoder.dimensions().unwrap();
-        tiff.write_image::<colortype::RGB8>(width, height, &image_data)
-            .unwrap();
-    }
-    file.seek(SeekFrom::Start(0)).unwrap();
-    {
-        let mut decoder = Decoder::new(&mut file).unwrap();
-        if let DecodingResult::U8(img_res) = decoder.read_image().unwrap() {
-            assert_eq!(image_data, img_res);
-        } else {
-            panic!("Wrong data type");
-        }
-    }
+#[test]
+fn test_cmyka_u8_roundtrip() {
+    test_u8_roundtrip::<colortype::CMYKA8>("cmyk-4c-8b.tiff", ColorType::CMYKA(8));
 }
 
 #[test]
 fn test_gray_u16_roundtrip() {
-    let img_file =
-        File::open("./tests/images/minisblack-1c-16b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::Gray(16));
+    test_u16_roundtrip::<colortype::Gray16>("minisblack-1c-16b.tiff", ColorType::Gray(16));
+}
 
-    let image_data = match decoder.read_image().unwrap() {
-        DecodingResult::U16(res) => res,
-        _ => panic!("Wrong data type"),
-    };
-
-    let mut file = tempfile::tempfile().unwrap();
-    {
-        let mut tiff = TiffEncoder::new(&mut file).unwrap();
-
-        let (width, height) = decoder.dimensions().unwrap();
-        tiff.write_image::<colortype::Gray16>(width, height, &image_data)
-            .unwrap();
-    }
-    file.seek(SeekFrom::Start(0)).unwrap();
-    {
-        let mut decoder = Decoder::new(&mut file).unwrap();
-        if let DecodingResult::U16(img_res) = decoder.read_image().unwrap() {
-            assert_eq!(image_data, img_res);
-        } else {
-            panic!("Wrong data type");
-        }
-    }
+#[test]
+fn test_gray_i16_roundtrip() {
+    test_i16_roundtrip::<colortype::GrayI16>("minisblack-1c-i16b.tiff", ColorType::Gray(16));
 }
 
 #[test]
 fn test_rgb_u16_roundtrip() {
-    let img_file = File::open("./tests/images/rgb-3c-16b.tiff").expect("Cannot find test image!");
-    let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
-    assert_eq!(decoder.colortype().unwrap(), ColorType::RGB(16));
+    test_u16_roundtrip::<colortype::RGB16>("rgb-3c-16b.tiff", ColorType::RGB(16));
+}
 
-    let image_data = match decoder.read_image().unwrap() {
-        DecodingResult::U16(res) => res,
-        _ => panic!("Wrong data type"),
-    };
+#[test]
+fn test_cmyk_u16_roundtrip() {
+    test_u16_roundtrip::<colortype::CMYK16>("cmyk-3c-16b.tiff", ColorType::CMYK(16));
+}
 
-    let mut file = tempfile::tempfile().unwrap();
-    {
-        let mut tiff = TiffEncoder::new(&mut file).unwrap();
+#[test]
+fn test_gray_u32_roundtrip() {
+    test_u32_roundtrip::<colortype::Gray32>("gradient-1c-32b.tiff", ColorType::Gray(32));
+}
 
-        let (width, height) = decoder.dimensions().unwrap();
-        tiff.write_image::<colortype::RGB16>(width, height, &image_data)
-            .unwrap();
+#[test]
+fn test_rgb_u32_roundtrip() {
+    test_u32_roundtrip::<colortype::RGB32>("gradient-3c-32b.tiff", ColorType::RGB(32));
+}
+
+#[test]
+fn test_gray_u64_roundtrip() {
+    test_u64_roundtrip::<colortype::Gray64>("gradient-1c-64b.tiff", ColorType::Gray(64));
+}
+
+#[test]
+fn test_rgb_u64_roundtrip() {
+    test_u64_roundtrip::<colortype::RGB64>("gradient-3c-64b.tiff", ColorType::RGB(64));
+}
+
+#[test]
+fn test_gray_f32_roundtrip() {
+    test_f32_roundtrip::<colortype::Gray32Float>("gradient-1c-32b-float.tiff", ColorType::Gray(32));
+}
+
+#[test]
+fn test_rgb_f32_roundtrip() {
+    test_f32_roundtrip::<colortype::RGB32Float>("gradient-3c-32b-float.tiff", ColorType::RGB(32));
+}
+
+#[test]
+fn test_cmyk_f32_roundtrip() {
+    test_f32_roundtrip::<colortype::CMYK32Float>("cmyk-3c-32b-float.tiff", ColorType::CMYK(32));
+}
+
+#[test]
+fn test_gray_f64_roundtrip() {
+    test_f64_roundtrip::<colortype::Gray64Float>("gradient-1c-64b-float.tiff", ColorType::Gray(64));
+}
+
+#[test]
+fn test_ycbcr_u8_roundtrip() {
+    test_u8_roundtrip::<colortype::YCbCr8>("tiled-jpeg-ycbcr.tif", ColorType::YCbCr(8));
+}
+
+trait AssertDecode {
+    fn assert_tag_u32(&mut self, tag: u16) -> u32;
+    fn assert_tag_u32_vec(&mut self, tag: u16) -> Vec<u32>;
+    fn assert_tag_i32(&mut self, tag: u16) -> i32;
+    fn assert_tag_i32_vec(&mut self, tag: u16) -> Vec<i32>;
+    fn assert_tag_u64(&mut self, tag: u16) -> u64;
+    fn assert_tag_u64_vec(&mut self, tag: u16) -> Vec<u64>;
+    fn assert_tag_i64(&mut self, tag: u16) -> i64;
+    fn assert_tag_i64_vec(&mut self, tag: u16) -> Vec<i64>;
+}
+
+impl<R: std::io::Read + std::io::Seek> AssertDecode for Decoder<R> {
+    fn assert_tag_u32(&mut self, tag: u16) -> u32 {
+        self.get_tag(Tag::Unknown(tag)).unwrap().into_u32().unwrap()
     }
-    file.seek(SeekFrom::Start(0)).unwrap();
-    {
-        let mut decoder = Decoder::new(&mut file).unwrap();
-        if let DecodingResult::U16(img_res) = decoder.read_image().unwrap() {
-            assert_eq!(image_data, img_res);
-        } else {
-            panic!("Wrong data type");
-        }
+    fn assert_tag_u32_vec(&mut self, tag: u16) -> Vec<u32> {
+        self.get_tag(Tag::Unknown(tag))
+            .unwrap()
+            .into_u32_vec()
+            .unwrap()
+    }
+    fn assert_tag_i32(&mut self, tag: u16) -> i32 {
+        self.get_tag(Tag::Unknown(tag)).unwrap().into_i32().unwrap()
+    }
+    fn assert_tag_i32_vec(&mut self, tag: u16) -> Vec<i32> {
+        self.get_tag(Tag::Unknown(tag))
+            .unwrap()
+            .into_i32_vec()
+            .unwrap()
+    }
+    fn assert_tag_u64(&mut self, tag: u16) -> u64 {
+        self.get_tag(Tag::Unknown(tag)).unwrap().into_u64().unwrap()
+    }
+    fn assert_tag_u64_vec(&mut self, tag: u16) -> Vec<u64> {
+        self.get_tag(Tag::Unknown(tag))
+            .unwrap()
+            .into_u64_vec()
+            .unwrap()
+    }
+    fn assert_tag_i64(&mut self, tag: u16) -> i64 {
+        self.get_tag(Tag::Unknown(tag)).unwrap().into_i64().unwrap()
+    }
+    fn assert_tag_i64_vec(&mut self, tag: u16) -> Vec<i64> {
+        self.get_tag(Tag::Unknown(tag))
+            .unwrap()
+            .into_i64_vec()
+            .unwrap()
     }
 }
 
@@ -184,24 +425,33 @@ fn test_multiple_byte() {
     {
         let mut tiff = TiffEncoder::new(&mut data).unwrap();
         let mut image_encoder = tiff.new_image::<colortype::Gray8>(1, 1).unwrap();
+        image_encoder.write_strip(&[1]).unwrap();
         let encoder = image_encoder.encoder();
 
-        encoder.write_tag(Tag::Unknown(65000), &[1_u8][..]);
-        encoder.write_tag(Tag::Unknown(65001), &[1_u8, 2][..]);
-        encoder.write_tag(Tag::Unknown(65002), &[1_u8, 2, 3][..]);
-        encoder.write_tag(Tag::Unknown(65003), &[1_u8, 2, 3, 4][..]);
-        encoder.write_tag(Tag::Unknown(65004), &[1_u8, 2, 3, 4, 5][..]);
+        encoder.write_tag(Tag::Unknown(65000), &[1_u8][..]).unwrap();
+        encoder
+            .write_tag(Tag::Unknown(65001), &[1_u8, 2][..])
+            .unwrap();
+        encoder
+            .write_tag(Tag::Unknown(65002), &[1_u8, 2, 3][..])
+            .unwrap();
+        encoder
+            .write_tag(Tag::Unknown(65003), &[1_u8, 2, 3, 4][..])
+            .unwrap();
+        encoder
+            .write_tag(Tag::Unknown(65004), &[1_u8, 2, 3, 4, 5][..])
+            .unwrap();
     }
 
     data.set_position(0);
     {
         let mut decoder = Decoder::new(&mut data).unwrap();
 
-        assert_eq!(decoder.get_tag(Tag::Unknown(65000)).unwrap().into_u32_vec().unwrap(), [1]);
-        assert_eq!(decoder.get_tag(Tag::Unknown(65001)).unwrap().into_u32_vec().unwrap(), [1, 2]);
-        assert_eq!(decoder.get_tag(Tag::Unknown(65002)).unwrap().into_u32_vec().unwrap(), [1, 2, 3]);
-        assert_eq!(decoder.get_tag(Tag::Unknown(65003)).unwrap().into_u32_vec().unwrap(), [1, 2, 3, 4]);
-        assert_eq!(decoder.get_tag(Tag::Unknown(65004)).unwrap().into_u32_vec().unwrap(), [1, 2, 3, 4, 5]);
+        assert_eq!(decoder.assert_tag_u32_vec(65000), [1]);
+        assert_eq!(decoder.assert_tag_u32_vec(65001), [1, 2]);
+        assert_eq!(decoder.assert_tag_u32_vec(65002), [1, 2, 3]);
+        assert_eq!(decoder.assert_tag_u32_vec(65003), [1, 2, 3, 4]);
+        assert_eq!(decoder.assert_tag_u32_vec(65004), [1, 2, 3, 4, 5]);
     }
 }
 
@@ -209,31 +459,68 @@ fn test_multiple_byte() {
 /// Test writing signed tags from TIFF 6.0
 fn test_signed() {
     let mut data = Cursor::new(Vec::new());
+    fn make_srational(i: i32) -> SRational {
+        SRational { n: i, d: 100 }
+    }
 
     {
         let mut tiff = TiffEncoder::new(&mut data).unwrap();
         let mut image_encoder = tiff.new_image::<colortype::Gray8>(1, 1).unwrap();
+        image_encoder.write_strip(&[1]).unwrap();
         let encoder = image_encoder.encoder();
 
         //Use the "reusable" tags section as per the TIFF6 spec
-        encoder.write_tag(Tag::Unknown(65000), -1_i8);
-        encoder.write_tag(Tag::Unknown(65001), &[-1_i8][..]);
-        encoder.write_tag(Tag::Unknown(65002), &[-1_i8, 2][..]);
-        encoder.write_tag(Tag::Unknown(65003), &[-1_i8, 2, -3][..]);
-        encoder.write_tag(Tag::Unknown(65004), &[-1_i8, 2, -3, 4][..]);
-        encoder.write_tag(Tag::Unknown(65005), &[-1_i8, 2, -3, 4, -5][..]);
+        encoder.write_tag(Tag::Unknown(65000), -1_i8).unwrap();
+        encoder
+            .write_tag(Tag::Unknown(65001), &[-1_i8][..])
+            .unwrap();
+        encoder
+            .write_tag(Tag::Unknown(65002), &[-1_i8, 2][..])
+            .unwrap();
+        encoder
+            .write_tag(Tag::Unknown(65003), &[-1_i8, 2, -3][..])
+            .unwrap();
+        encoder
+            .write_tag(Tag::Unknown(65004), &[-1_i8, 2, -3, 4][..])
+            .unwrap();
+        encoder
+            .write_tag(Tag::Unknown(65005), &[-1_i8, 2, -3, 4, -5][..])
+            .unwrap();
 
-        encoder.write_tag(Tag::Unknown(65010), -1_i16);
-        encoder.write_tag(Tag::Unknown(65011), -1_i16);
-        encoder.write_tag(Tag::Unknown(65012), &[-1_i16, 2][..]);
-        encoder.write_tag(Tag::Unknown(65013), &[-1_i16, 2, -3][..]);
+        encoder.write_tag(Tag::Unknown(65010), -1_i16).unwrap();
+        encoder.write_tag(Tag::Unknown(65011), -1_i16).unwrap();
+        encoder
+            .write_tag(Tag::Unknown(65012), &[-1_i16, 2][..])
+            .unwrap();
+        encoder
+            .write_tag(Tag::Unknown(65013), &[-1_i16, 2, -3][..])
+            .unwrap();
 
-        encoder.write_tag(Tag::Unknown(65020), -1_i32);
-        encoder.write_tag(Tag::Unknown(65021), &[-1_i32][..]);
-        encoder.write_tag(Tag::Unknown(65022), &[-1_i32, 2][..]);
+        encoder.write_tag(Tag::Unknown(65020), -1_i32).unwrap();
+        encoder
+            .write_tag(Tag::Unknown(65021), &[-1_i32][..])
+            .unwrap();
+        encoder
+            .write_tag(Tag::Unknown(65022), &[-1_i32, 2][..])
+            .unwrap();
 
-        encoder.write_tag(Tag::Unknown(65030), SRational { n: -1, d: 100 });
-        encoder.write_tag(Tag::Unknown(65031), &[SRational { n: -1, d: 100 }, SRational { n: 2, d: 100 }][..]);
+        encoder.write_tag(Tag::Unknown(65030), -1_i64).unwrap();
+        encoder
+            .write_tag(Tag::Unknown(65031), &[-1_i64][..])
+            .unwrap();
+        encoder
+            .write_tag(Tag::Unknown(65032), &[-1_i64, 2][..])
+            .unwrap();
+
+        encoder
+            .write_tag(Tag::Unknown(65040), make_srational(-1))
+            .unwrap();
+        encoder
+            .write_tag(
+                Tag::Unknown(65041),
+                &[make_srational(-1), make_srational(2)][..],
+            )
+            .unwrap();
     }
 
     //Rewind the cursor for reading
@@ -241,24 +528,28 @@ fn test_signed() {
     {
         let mut decoder = Decoder::new(&mut data).unwrap();
 
-        assert_eq!(decoder.get_tag(Tag::Unknown(65000)).unwrap().into_i32().unwrap(), -1, );
-        assert_eq!(decoder.get_tag(Tag::Unknown(65001)).unwrap().into_i32_vec().unwrap(), [-1]);
-        assert_eq!(decoder.get_tag(Tag::Unknown(65002)).unwrap().into_i32_vec().unwrap(), [-1, 2]);
-        assert_eq!(decoder.get_tag(Tag::Unknown(65003)).unwrap().into_i32_vec().unwrap(), [-1, 2, -3]);
-        assert_eq!(decoder.get_tag(Tag::Unknown(65004)).unwrap().into_i32_vec().unwrap(), [-1, 2, -3, 4]);
-        assert_eq!(decoder.get_tag(Tag::Unknown(65005)).unwrap().into_i32_vec().unwrap(), [-1, 2, -3, 4, -5], );
+        assert_eq!(decoder.assert_tag_i32(65000), -1);
+        assert_eq!(decoder.assert_tag_i32_vec(65001), [-1]);
+        assert_eq!(decoder.assert_tag_i32_vec(65002), [-1, 2]);
+        assert_eq!(decoder.assert_tag_i32_vec(65003), [-1, 2, -3]);
+        assert_eq!(decoder.assert_tag_i32_vec(65004), [-1, 2, -3, 4]);
+        assert_eq!(decoder.assert_tag_i32_vec(65005), [-1, 2, -3, 4, -5],);
 
-        assert_eq!(decoder.get_tag(Tag::Unknown(65010)).unwrap().into_i32().unwrap(), -1);
-        assert_eq!(decoder.get_tag(Tag::Unknown(65011)).unwrap().into_i32_vec().unwrap(), [-1]);
-        assert_eq!(decoder.get_tag(Tag::Unknown(65012)).unwrap().into_i32_vec().unwrap(), [-1, 2]);
-        assert_eq!(decoder.get_tag(Tag::Unknown(65013)).unwrap().into_i32_vec().unwrap(), [-1, 2, -3]);
+        assert_eq!(decoder.assert_tag_i32(65010), -1);
+        assert_eq!(decoder.assert_tag_i32_vec(65011), [-1]);
+        assert_eq!(decoder.assert_tag_i32_vec(65012), [-1, 2]);
+        assert_eq!(decoder.assert_tag_i32_vec(65013), [-1, 2, -3]);
 
-        assert_eq!(decoder.get_tag(Tag::Unknown(65020)).unwrap().into_i32().unwrap(), -1);
-        assert_eq!(decoder.get_tag(Tag::Unknown(65021)).unwrap().into_i32_vec().unwrap(), [-1]);
-        assert_eq!(decoder.get_tag(Tag::Unknown(65022)).unwrap().into_i32_vec().unwrap(), [-1, 2]);
+        assert_eq!(decoder.assert_tag_i32(65020), -1);
+        assert_eq!(decoder.assert_tag_i32_vec(65021), [-1]);
+        assert_eq!(decoder.assert_tag_i32_vec(65022), [-1, 2]);
 
-        assert_eq!(decoder.get_tag(Tag::Unknown(65030)).unwrap().into_i32_vec().unwrap(), [-1, 100]);
-        assert_eq!(decoder.get_tag(Tag::Unknown(65031)).unwrap().into_i32_vec().unwrap(), [-1_i32, 100, 2, 100]);
+        assert_eq!(decoder.assert_tag_i64(65030), -1);
+        assert_eq!(decoder.assert_tag_i64_vec(65031), [-1]);
+        assert_eq!(decoder.assert_tag_i64_vec(65032), [-1, 2]);
+
+        assert_eq!(decoder.assert_tag_i32_vec(65040), [-1, 100]);
+        assert_eq!(decoder.assert_tag_i32_vec(65041), [-1_i32, 100, 2, 100]);
     }
 }
 
@@ -273,10 +564,14 @@ fn test_multipage_image() {
 
         // write first grayscale image (2x2 16-bit)
         let img1: Vec<u16> = [1, 2, 3, 4].to_vec();
-        img_encoder.write_image::<colortype::Gray16>(2, 2, &img1[..]);
+        img_encoder
+            .write_image::<colortype::Gray16>(2, 2, &img1[..])
+            .unwrap();
         // write second grayscale image (3x3 8-bit)
         let img2: Vec<u8> = [9, 8, 7, 6, 5, 4, 3, 2, 1].to_vec();
-        img_encoder.write_image::<colortype::Gray8>(3, 3, &img2[..]);
+        img_encoder
+            .write_image::<colortype::Gray8>(3, 3, &img2[..])
+            .unwrap();
     }
 
     // seek to the beginning of the file, so that it can be decoded
@@ -292,3 +587,98 @@ fn test_multipage_image() {
         assert_eq!(img_decoder.dimensions().unwrap(), (3, 3));
     }
 }
+
+#[test]
+/// verify rows per strip setting
+fn test_rows_per_strip() {
+    let mut file = Cursor::new(Vec::new());
+    {
+        let mut img_encoder = TiffEncoder::new(&mut file).unwrap();
+
+        let mut image = img_encoder.new_image::<colortype::Gray8>(100, 100).unwrap();
+        assert_eq!(image.next_strip_sample_count(), 100 * 100);
+        image.rows_per_strip(2).unwrap();
+        assert_eq!(image.next_strip_sample_count(), 2 * 100);
+
+        let img2: Vec<u8> = vec![0; 2 * 100];
+        image.write_strip(&img2[..]).unwrap();
+        assert!(image.rows_per_strip(5).is_err());
+        for i in 1..50 {
+            let img2: Vec<u8> = vec![i; 2 * 100];
+            image.write_strip(&img2[..]).unwrap();
+        }
+        assert!(image.write_strip(&img2[..]).is_err());
+        image.finish().unwrap();
+    }
+
+    file.seek(SeekFrom::Start(0)).unwrap();
+    {
+        let mut decoder = Decoder::new(&mut file).unwrap();
+        assert_eq!(decoder.get_tag_u64(Tag::RowsPerStrip).unwrap(), 2);
+        assert_eq!(decoder.strip_count().unwrap(), 50);
+
+        for i in 0..50 {
+            let img2 = [i; 2 * 100];
+            match decoder.read_chunk(i as u32).unwrap() {
+                DecodingResult::U8(data) => assert_eq!(&img2[..], &data[..]),
+                other => panic!("Incorrect strip type {:?}", other),
+            }
+        }
+    }
+}
+
+#[test]
+fn test_auxiliary_directory() {
+    const ARTIST: &str = "Auxiliary-tiff";
+
+    let mut data = Cursor::new(Vec::new());
+    let mut tiff = TiffEncoder::new(&mut data).unwrap();
+
+    {
+        let mut image_encoder = tiff.new_image::<colortype::Gray8>(1, 1).unwrap();
+        image_encoder.write_strip(&[1]).unwrap();
+    }
+
+    let exif = {
+        let mut extra = tiff.extra_directory().unwrap();
+        extra.write_tag(Tag::Artist, ARTIST).unwrap();
+        extra.finish_with_offsets().unwrap()
+    };
+
+    {
+        let mut image_encoder = tiff.new_image::<colortype::Gray8>(2, 1).unwrap();
+        image_encoder.write_strip(&[1, 2]).unwrap();
+        let encoder = image_encoder.encoder();
+        encoder.write_tag(Tag::ExifDirectory, exif.offset).unwrap();
+    }
+
+    drop(tiff);
+
+    data.set_position(0);
+    let mut decoder = Decoder::new(&mut data).unwrap();
+
+    {
+        assert_eq!(decoder.dimensions().unwrap(), (1, 1));
+        let _ = decoder.read_image().unwrap();
+    }
+
+    {
+        decoder.next_image().unwrap();
+        assert_eq!(decoder.dimensions().unwrap(), (2, 1));
+        let _ = decoder.read_image().unwrap();
+
+        let exif_location = decoder
+            .get_tag(Tag::ExifDirectory)
+            .expect("second directory missing Exif")
+            .into_ifd_pointer()
+            .expect("exif directory is not an IFD pointer");
+
+        let exif = decoder.read_directory(exif_location).unwrap();
+
+        let artist = decoder
+            .read_directory_tags(&exif)
+            .get_tag_ascii_string(Tag::Artist)
+            .expect("EXIF directory missing artist tag");
+        assert_eq!(artist, ARTIST);
+    }
+}

tests/encode_images_with_compression.rs

@@ -0,0 +1,158 @@
+extern crate tiff;
+
+use std::io::{Cursor, Seek, Write};
+use tiff::{
+    decoder::{Decoder, DecodingResult},
+    encoder::{
+        colortype::{self, ColorType},
+        compression::*,
+        Compression, TiffEncoder, TiffValue,
+    },
+};
+
+trait TestImage<const NUM_CHANNELS: usize>: From<Vec<<Self::Color as ColorType>::Inner>> {
+    const WIDTH: u32;
+    const HEIGHT: u32;
+    type Color: ColorType;
+
+    fn reference_data(&self) -> &[<Self::Color as ColorType>::Inner];
+    fn generate_pixel(x: u32, y: u32) -> [<Self::Color as ColorType>::Inner; NUM_CHANNELS];
+
+    fn compress<W: Write + Seek>(&self, encoder: &mut TiffEncoder<W>)
+    where
+        [<Self::Color as ColorType>::Inner]: TiffValue,
+    {
+        let image = encoder
+            .new_image::<Self::Color>(Self::WIDTH, Self::HEIGHT)
+            .unwrap();
+        image.write_data(self.reference_data()).unwrap();
+    }
+
+    fn generate() -> Self {
+        assert_eq!(
+            Self::Color::BITS_PER_SAMPLE.len(),
+            NUM_CHANNELS,
+            "Incompatible color type"
+        );
+
+        let mut data = Vec::with_capacity((Self::WIDTH * Self::HEIGHT) as usize * NUM_CHANNELS);
+        for x in 0..Self::WIDTH {
+            for y in 0..Self::HEIGHT {
+                data.extend(IntoIterator::into_iter(Self::generate_pixel(x, y)));
+            }
+        }
+        Self::from(data)
+    }
+}
+
+struct TestImageColor(Vec<u16>);
+
+impl From<Vec<u16>> for TestImageColor {
+    fn from(value: Vec<u16>) -> Self {
+        Self(value)
+    }
+}
+
+impl TestImage<3> for TestImageColor {
+    const WIDTH: u32 = 1;
+    const HEIGHT: u32 = 7;
+    type Color = colortype::RGB16;
+
+    fn reference_data(&self) -> &[u16] {
+        &self.0
+    }
+
+    fn generate_pixel(x: u32, y: u32) -> [<Self::Color as ColorType>::Inner; 3] {
+        let val = (x + y) % <Self::Color as ColorType>::Inner::MAX as u32;
+        [val as <Self::Color as ColorType>::Inner; 3]
+    }
+}
+
+struct TestImageGrayscale(Vec<u8>);
+
+impl From<Vec<u8>> for TestImageGrayscale {
+    fn from(value: Vec<u8>) -> Self {
+        Self(value)
+    }
+}
+
+impl TestImage<1> for TestImageGrayscale {
+    const WIDTH: u32 = 21;
+    const HEIGHT: u32 = 10;
+    type Color = colortype::Gray8;
+
+    fn reference_data(&self) -> &[u8] {
+        &self.0
+    }
+
+    fn generate_pixel(x: u32, y: u32) -> [<Self::Color as ColorType>::Inner; 1] {
+        let val = (x + y) % <Self::Color as ColorType>::Inner::MAX as u32;
+        [val as <Self::Color as ColorType>::Inner]
+    }
+}
+
+fn encode_decode_with_compression(compression: Compression) {
+    let mut data = Cursor::new(Vec::new());
+
+    let image_rgb = TestImageColor::generate();
+    let image_grayscale = TestImageGrayscale::generate();
+
+    // Encode tiff with compression
+    {
+        // Create a multipage image with 2 images
+        let mut encoder = TiffEncoder::new(&mut data)
+            .unwrap()
+            .with_compression(compression);
+        image_rgb.compress(&mut encoder);
+        image_grayscale.compress(&mut encoder);
+    }
+
+    // Decode tiff
+    data.set_position(0);
+    {
+        let mut decoder = Decoder::new(data).unwrap();
+
+        // Check the RGB image
+        assert_eq!(
+            match decoder.read_image() {
+                Ok(DecodingResult::U16(image_data)) => image_data,
+                unexpected => panic!("Descoding RGB failed: {:?}", unexpected),
+            },
+            image_rgb.reference_data()
+        );
+
+        // Check the grayscale image
+        decoder.next_image().unwrap();
+        assert_eq!(
+            match decoder.read_image() {
+                Ok(DecodingResult::U8(image_data)) => image_data,
+                unexpected => panic!("Decoding grayscale failed: {:?}", unexpected),
+            },
+            image_grayscale.reference_data()
+        );
+    }
+}
+
+#[test]
+fn encode_decode_without_compression() {
+    encode_decode_with_compression(Compression::Uncompressed);
+}
+
+#[test]
+#[cfg(feature = "lzw")]
+fn encode_decode_with_lzw() {
+    encode_decode_with_compression(Compression::Lzw);
+}
+
+#[test]
+#[cfg(feature = "deflate")]
+fn encode_decode_with_deflate() {
+    encode_decode_with_compression(Compression::Deflate(DeflateLevel::Fast));
+    encode_decode_with_compression(Compression::Deflate(DeflateLevel::Balanced));
+    encode_decode_with_compression(Compression::Deflate(DeflateLevel::Best));
+}
+
+#[test]
+fn encode_decode_with_packbits() {
+    encode_decode_with_compression(Compression::Packbits);
+}

tests/predict.rs

@@ -0,0 +1,231 @@
+extern crate tiff;
+
+use tiff::decoder::{Decoder, DecodingResult};
+use tiff::encoder::{colortype, Compression, Predictor, TiffEncoder};
+use tiff::ColorType;
+
+use std::fs::File;
+use std::io::{Cursor, Seek, SeekFrom};
+use std::path::PathBuf;
+
+const TEST_IMAGE_DIR: &str = "./tests/images/";
+
+macro_rules! test_predict {
+    ($name:ident, $buffer:ident, $buffer_ty:ty) => {
+        fn $name<C: colortype::ColorType<Inner = $buffer_ty>>(
+            file: &str,
+            expected_type: ColorType,
+        ) {
+            let path = PathBuf::from(TEST_IMAGE_DIR).join(file);
+            let file = File::open(path).expect("Cannot find test image!");
+            let mut decoder = Decoder::new(file).expect("Cannot create decoder!");
+
+            assert_eq!(decoder.colortype().unwrap(), expected_type);
+            let image_data = match decoder.read_image().unwrap() {
+                DecodingResult::$buffer(res) => res,
+                _ => panic!("Wrong data type"),
+            };
+
+            let mut predicted = Vec::with_capacity(image_data.len());
+            C::horizontal_predict(&image_data, &mut predicted);
+
+            let sample_size = C::SAMPLE_FORMAT.len();
+
+            (0..sample_size).for_each(|i| {
+                assert_eq!(predicted[i], image_data[i]);
+            });
+
+            (sample_size..image_data.len()).for_each(|i| {
+                predicted[i] = predicted[i].wrapping_add(predicted[i - sample_size]);
+                assert_eq!(predicted[i], image_data[i]);
+            });
+        }
+    };
+}
+
+test_predict!(test_u8_predict, U8, u8);
+test_predict!(test_i8_predict, I8, i8);
+test_predict!(test_u16_predict, U16, u16);
+test_predict!(test_i16_predict, I16, i16);
+test_predict!(test_u32_predict, U32, u32);
+test_predict!(test_u64_predict, U64, u64);
+
+#[test]
+fn test_gray_u8_predict() {
+    test_u8_predict::<colortype::Gray8>("minisblack-1c-8b.tiff", ColorType::Gray(8));
+}
+
+#[test]
+fn test_gray_i8_predict() {
+    test_i8_predict::<colortype::GrayI8>("minisblack-1c-i8b.tiff", ColorType::Gray(8));
+}
+
+#[test]
+fn test_rgb_u8_predict() {
+    test_u8_predict::<colortype::RGB8>("rgb-3c-8b.tiff", ColorType::RGB(8));
+}
+
+#[test]
+fn test_cmyk_u8_predict() {
+    test_u8_predict::<colortype::CMYK8>("cmyk-3c-8b.tiff", ColorType::CMYK(8));
+}
+
+#[test]
+fn test_gray_u16_predict() {
+    test_u16_predict::<colortype::Gray16>("minisblack-1c-16b.tiff", ColorType::Gray(16));
+}
+
+#[test]
+fn test_gray_i16_predict() {
+    test_i16_predict::<colortype::GrayI16>("minisblack-1c-i16b.tiff", ColorType::Gray(16));
+}
+
+#[test]
+fn test_rgb_u16_predict() {
+    test_u16_predict::<colortype::RGB16>("rgb-3c-16b.tiff", ColorType::RGB(16));
+}
+
+#[test]
+fn test_cmyk_u16_predict() {
+    test_u16_predict::<colortype::CMYK16>("cmyk-3c-16b.tiff", ColorType::CMYK(16));
+}
+
+#[test]
+fn test_gray_u32_predict() {
+    test_u32_predict::<colortype::Gray32>("gradient-1c-32b.tiff", ColorType::Gray(32));
+}
+
+#[test]
+fn test_rgb_u32_predict() {
+    test_u32_predict::<colortype::RGB32>("gradient-3c-32b.tiff", ColorType::RGB(32));
+}
+
+#[test]
+fn test_gray_u64_predict() {
+    test_u64_predict::<colortype::Gray64>("gradient-1c-64b.tiff", ColorType::Gray(64));
+}
+
+#[test]
+fn test_rgb_u64_predict() {
+    test_u64_predict::<colortype::RGB64>("gradient-3c-64b.tiff", ColorType::RGB(64));
+}
+
+#[test]
+fn test_ycbcr_u8_predict() {
+    test_u8_predict::<colortype::YCbCr8>("tiled-jpeg-ycbcr.tif", ColorType::YCbCr(8));
+}
+
+macro_rules! test_predict_roundtrip {
+    ($name:ident, $buffer:ident, $buffer_ty:ty) => {
+        fn $name<C: colortype::ColorType<Inner = $buffer_ty>>(
+            file: &str,
+            expected_type: ColorType,
+        ) {
+            let path = PathBuf::from(TEST_IMAGE_DIR).join(file);
+            let img_file = File::open(path).expect("Cannot find test image!");
+            let mut decoder = Decoder::new(img_file).expect("Cannot create decoder");
+            assert_eq!(decoder.colortype().unwrap(), expected_type);
+
+            let image_data = match decoder.read_image().unwrap() {
+                DecodingResult::$buffer(res) => res,
+                _ => panic!("Wrong data type"),
+            };
+
+            let mut file = Cursor::new(Vec::new());
+            {
+                let mut tiff = TiffEncoder::new(&mut file)
+                    .unwrap()
+                    .with_predictor(Predictor::Horizontal);
+
+                let (width, height) = decoder.dimensions().unwrap();
+                tiff.write_image::<C>(width, height, &image_data).unwrap();
+            }
+            file.seek(SeekFrom::Start(0)).unwrap();
+            {
+                let mut decoder = Decoder::new(&mut file).unwrap();
+                if let DecodingResult::$buffer(img_res) =
+                    decoder.read_image().expect("Decoding image failed")
+                {
+                    assert_eq!(image_data, img_res);
+                } else {
+                    panic!("Wrong data type");
+                }
+            }
+        }
+    };
+}
+
+test_predict_roundtrip!(test_u8_predict_roundtrip, U8, u8);
+test_predict_roundtrip!(test_i8_predict_roundtrip, I8, i8);
+test_predict_roundtrip!(test_u16_predict_roundtrip, U16, u16);
+test_predict_roundtrip!(test_i16_predict_roundtrip, I16, i16);
+test_predict_roundtrip!(test_u32_predict_roundtrip, U32, u32);
+test_predict_roundtrip!(test_u64_predict_roundtrip, U64, u64);
+
+#[test]
+fn test_gray_u8_predict_roundtrip() {
+    test_u8_predict_roundtrip::<colortype::Gray8>("minisblack-1c-8b.tiff", ColorType::Gray(8));
+}
+
+#[test]
+fn test_gray_i8_predict_roundtrip() {
+    test_i8_predict_roundtrip::<colortype::GrayI8>("minisblack-1c-i8b.tiff", ColorType::Gray(8));
+}
+
+#[test]
+fn test_rgb_u8_predict_roundtrip() {
+    test_u8_predict_roundtrip::<colortype::RGB8>("rgb-3c-8b.tiff", ColorType::RGB(8));
+}
+
+#[test]
+fn test_cmyk_u8_predict_roundtrip() {
+    test_u8_predict_roundtrip::<colortype::CMYK8>("cmyk-3c-8b.tiff", ColorType::CMYK(8));
+}
+
+#[test]
+fn test_gray_u16_predict_roundtrip() {
+    test_u16_predict_roundtrip::<colortype::Gray16>("minisblack-1c-16b.tiff", ColorType::Gray(16));
+}
+
+#[test]
+fn test_gray_i16_predict_roundtrip() {
+    test_i16_predict_roundtrip::<colortype::GrayI16>(
+        "minisblack-1c-i16b.tiff",
+        ColorType::Gray(16),
+    );
+}
+
+#[test]
+fn test_rgb_u16_predict_roundtrip() {
+    test_u16_predict_roundtrip::<colortype::RGB16>("rgb-3c-16b.tiff", ColorType::RGB(16));
+}
+
+#[test]
+fn test_cmyk_u16_predict_roundtrip() {
+    test_u16_predict_roundtrip::<colortype::CMYK16>("cmyk-3c-16b.tiff", ColorType::CMYK(16));
+}
+
+#[test]
+fn test_gray_u32_predict_roundtrip() {
+    test_u32_predict_roundtrip::<colortype::Gray32>("gradient-1c-32b.tiff", ColorType::Gray(32));
+}
+
+#[test]
+fn test_rgb_u32_predict_roundtrip() {
+    test_u32_predict_roundtrip::<colortype::RGB32>("gradient-3c-32b.tiff", ColorType::RGB(32));
+}
+
+#[test]
+fn test_gray_u64_predict_roundtrip() {
+    test_u64_predict_roundtrip::<colortype::Gray64>("gradient-1c-64b.tiff", ColorType::Gray(64));
+}
+
+#[test]
+fn test_rgb_u64_predict_roundtrip() {
+    test_u64_predict_roundtrip::<colortype::RGB64>("gradient-3c-64b.tiff", ColorType::RGB(64));
+}
+
+#[test]
+fn test_ycbcr_u8_predict_roundtrip() {
+    test_u8_predict_roundtrip::<colortype::YCbCr8>("tiled-jpeg-ycbcr.tif", ColorType::YCbCr(8));
+}

tests/subsubifds.rs

@@ -0,0 +1,41 @@
+use tiff::decoder::Decoder;
+
+// This file has the following IFD structure:
+//
+// ```
+// IFD -> IFD -> IFD
+//        |-> IFD
+//        |-> IFD -> IFD
+//        |          \-> IFD -> IFD
+//        \-> IFD
+// ```
+//
+// where the main chain of IFD has 3 images, the second of which has several sub-IFDs and some have
+// more nested IFDs.
+const TEST_IMAGE_SUBIFD: &str = "./tests/subsubifds.tif";
+use std::fs::File;
+
+#[test]
+fn decode_seek_chain() {
+    let file = File::open(TEST_IMAGE_SUBIFD).expect("Cannot open test image");
+    let mut decoder = Decoder::new(file).expect("Invalid format to create decoder");
+
+    // Remember the offsets in the first iteration.
+    let offset0 = decoder.ifd_pointer().expect("First IFD pointer not found");
+    decoder.next_image().unwrap();
+    let offset1 = decoder.ifd_pointer().expect("Second IFD pointer not found");
+    decoder.next_image().unwrap();
+    let offset2 = decoder.ifd_pointer().expect("Third IFD pointer not found");
+    assert!(!decoder.more_images());
+
+    // Ensure we can seek, to do this again.
+    decoder
+        .seek_to_image(0)
+        .expect("Failed to seek to first image");
+    assert_eq!(Some(offset0), decoder.ifd_pointer());
+    decoder.next_image().unwrap();
+    assert_eq!(Some(offset1), decoder.ifd_pointer());
+    decoder.next_image().unwrap();
+    assert_eq!(Some(offset2), decoder.ifd_pointer());
+    assert!(!decoder.more_images());
+}