Merge pull request #151 from mindQ-GmbH-Co-KG/compression-release

Add TIFF compression during encoding and corresponding tests

README.md

@@ -16,25 +16,25 @@ TIFF decoding and encoding library in pure Rust
 ### 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) |
-| `YCbCr` | | |
-| `CIELab` | | |
+| `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)              |
+| `YCbCr`                     |                                         |                           |
+| `CIELab`                    |                                         |                           |
 
 ### Compressions
 
-| | Decoding | Encoding |
-|-|-|-|
-| None | ✓ | ✓ |
-| LZW | ✓ | |
-| Deflate | ✓ | |
-| PackBits | ✓ | |
+|          | Decoding | Encoding |
+| -------- | -------- | -------- |
+| None     | ✓        | ✓        |
+| LZW      | ✓        | ✓        |
+| Deflate  | ✓        | ✓        |
+| PackBits | ✓        | ✓        |
 
 
 ## Not yet supported

benches/lzw.rs

@@ -33,7 +33,7 @@ fn main() {
                 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");

src/encoder/compression/deflate.rs

@@ -0,0 +1,83 @@
+use crate::{encoder::compression::*, tags::CompressionMethod};
+use flate2::{write::ZlibEncoder, Compression as FlateCompression};
+use std::io::Write;
+
+/// 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.clone())
+    }
+}
+
+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(&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 +1,47 @@
+use crate::{encoder::compression::*, tags::CompressionMethod};
+use std::io::Write;
+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::default().write_to(&mut writer, TEST_DATA).unwrap();
+        assert_eq!(EXPECTED_COMPRESSED_DATA, compressed_data.as_slice());
+    }
+}

src/encoder/compression/mod.rs

@@ -0,0 +1,60 @@
+use crate::tags::CompressionMethod;
+use std::io::{self, Write};
+
+mod deflate;
+mod lzw;
+mod packbits;
+mod uncompressed;
+
+pub use self::deflate::{Deflate, DeflateLevel};
+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.
+pub enum Compressor {
+    Uncompressed(Uncompressed),
+    Lzw(Lzw),
+    Deflate(Deflate),
+    Packbits(Packbits),
+}
+
+impl Default for Compressor {
+    /// The default compression strategy does not apply any compression.
+    fn default() -> Self {
+        Compressor::Uncompressed(Uncompressed::default())
+    }
+}
+
+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),
+            Compressor::Lzw(algorithm) => algorithm.write_to(writer, bytes),
+            Compressor::Deflate(algorithm) => algorithm.write_to(writer, bytes),
+            Compressor::Packbits(algorithm) => algorithm.write_to(writer, bytes),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    pub const TEST_DATA: &'static [u8] =
+        b"This is a string for checking various compression algorithms.";
+}

src/encoder/compression/packbits.rs

@@ -0,0 +1,213 @@
+use crate::{encoder::compression::*, tags::CompressionMethod};
+use std::io::{BufWriter, Error, ErrorKind, Write};
+
+/// 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(&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(&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(&bytes[pending_index..pending_index + bytes_pending as usize])?;
+        }
+
+        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::default()
+            .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: &'static [u8] =
+            b"This strrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrring hangs.";
+        const EXPECTED_COMPRESSED_DATA: &'static [u8] = b"\x06This st\xD1r\x09ing hangs.";
+
+        let mut compressed_data = Vec::<u8>::new();
+        let mut writer = Cursor::new(&mut compressed_data);
+        Packbits::default()
+            .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::default()
+            .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: &'static [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::default()
+            .write_to(&mut writer, &TEST_DATA)
+            .unwrap();
+        assert_eq!(compressed_data, EXPECTED_COMPRESSED_DATA);
+    }
+}

src/encoder/compression/uncompressed.rs

@@ -0,0 +1,37 @@
+use crate::{encoder::compression::*, tags::CompressionMethod};
+use std::io::Write;
+
+/// 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::default()
+            .write_to(&mut writer, TEST_DATA)
+            .unwrap();
+        assert_eq!(TEST_DATA, compressed_data);
+    }
+}

src/encoder/mod.rs

@@ -12,14 +12,16 @@ use std::{
 
 use crate::{
     error::TiffResult,
-    tags::{self, ResolutionUnit, Tag},
+    tags::{ResolutionUnit, Tag},
 };
 
 pub mod colortype;
+pub mod compression;
 mod tiff_value;
 mod writer;
 
 use self::colortype::*;
+use self::compression::*;
 use self::writer::*;
 
 /// Encoder for Tiff and BigTiff files.
@@ -98,11 +100,22 @@ impl<W: Write + Seek, K: TiffKind> TiffEncoder<W, K> {
         &mut self,
         width: u32,
         height: u32,
-    ) -> TiffResult<ImageEncoder<W, C, K>> {
+    ) -> TiffResult<ImageEncoder<W, C, K, Uncompressed>> {
         let encoder = DirectoryEncoder::new(&mut self.writer)?;
         ImageEncoder::new(encoder, width, height)
     }
 
+    /// Create an [`ImageEncoder`] to encode an image one slice at a time.
+    pub fn new_image_with_compression<C: ColorType, D: Compression>(
+        &mut self,
+        width: u32,
+        height: u32,
+        compression: D,
+    ) -> TiffResult<ImageEncoder<W, C, K, D>> {
+        let encoder = DirectoryEncoder::new(&mut self.writer)?;
+        ImageEncoder::with_compression(encoder, width, height, compression)
+    }
+
     /// Convenience function to write an entire image from memory.
     pub fn write_image<C: ColorType>(
         &mut self,
@@ -117,6 +130,23 @@ impl<W: Write + Seek, K: TiffKind> TiffEncoder<W, K> {
         let image: ImageEncoder<W, C, K> = ImageEncoder::new(encoder, width, height)?;
         image.write_data(data)
     }
+
+    /// Convenience function to write an entire image from memory with a given compression.
+    pub fn write_image_with_compression<C: ColorType, D: Compression>(
+        &mut self,
+        width: u32,
+        height: u32,
+        compression: D,
+        data: &[C::Inner],
+    ) -> TiffResult<()>
+    where
+        [C::Inner]: TiffValue,
+    {
+        let encoder = DirectoryEncoder::new(&mut self.writer)?;
+        let image: ImageEncoder<W, C, K, D> =
+            ImageEncoder::with_compression(encoder, width, height, compression)?;
+        image.write_data(data)
+    }
 }
 
 /// Low level interface to encode ifd directories.
@@ -216,6 +246,11 @@ impl<'a, W: 'a + Write + Seek, K: TiffKind> DirectoryEncoder<'a, W, K> {
         Ok(offset)
     }
 
+    /// Provides the number of bytes written by the underlying TiffWriter during the last call.
+    fn last_written(&self) -> u64 {
+        self.writer.last_written()
+    }
+
     fn finish_internal(&mut self) -> TiffResult<()> {
         let ifd_pointer = self.write_directory()?;
         let curr_pos = self.writer.offset();
@@ -277,7 +312,13 @@ impl<'a, W: Write + Seek, K: TiffKind> Drop for DirectoryEncoder<'a, W, K> {
 /// # }
 /// ```
 /// You can also call write_data function wich will encode by strip and finish
-pub struct ImageEncoder<'a, W: 'a + Write + Seek, C: ColorType, K: TiffKind> {
+pub struct ImageEncoder<
+    'a,
+    W: 'a + Write + Seek,
+    C: ColorType,
+    K: TiffKind,
+    D: Compression = Uncompressed,
+> {
     encoder: DirectoryEncoder<'a, W, K>,
     strip_idx: u64,
     strip_count: u64,
@@ -288,11 +329,26 @@ pub struct ImageEncoder<'a, W: 'a + Write + Seek, C: ColorType, K: TiffKind> {
     strip_offsets: Vec<K::OffsetType>,
     strip_byte_count: Vec<K::OffsetType>,
     dropped: bool,
+    compression: D,
     _phantom: ::std::marker::PhantomData<C>,
 }
 
-impl<'a, W: 'a + Write + Seek, T: ColorType, K: TiffKind> ImageEncoder<'a, W, T, K> {
-    fn new(mut encoder: DirectoryEncoder<'a, W, K>, width: u32, height: u32) -> TiffResult<Self> {
+impl<'a, W: 'a + Write + Seek, T: ColorType, K: TiffKind, D: Compression>
+    ImageEncoder<'a, W, T, K, D>
+{
+    fn new(encoder: DirectoryEncoder<'a, W, K>, width: u32, height: u32) -> TiffResult<Self>
+    where
+        D: Default,
+    {
+        Self::with_compression(encoder, width, height, D::default())
+    }
+
+    fn with_compression(
+        mut encoder: DirectoryEncoder<'a, W, K>,
+        width: u32,
+        height: u32,
+        compression: D,
+    ) -> TiffResult<Self> {
         let row_samples = u64::from(width) * u64::try_from(<T>::BITS_PER_SAMPLE.len())?;
         let row_bytes = row_samples * u64::from(<T::Inner>::BYTE_LEN);
 
@@ -304,7 +360,7 @@ impl<'a, W: 'a + Write + Seek, T: ColorType, K: TiffKind> ImageEncoder<'a, W, T,
 
         encoder.write_tag(Tag::ImageWidth, width)?;
         encoder.write_tag(Tag::ImageLength, height)?;
-        encoder.write_tag(Tag::Compression, tags::CompressionMethod::None.to_u16())?;
+        encoder.write_tag(Tag::Compression, D::COMPRESSION_METHOD.to_u16())?;
 
         encoder.write_tag(Tag::BitsPerSample, <T>::BITS_PER_SAMPLE)?;
         let sample_format: Vec<_> = <T>::SAMPLE_FORMAT.iter().map(|s| s.to_u16()).collect();
@@ -332,6 +388,7 @@ impl<'a, W: 'a + Write + Seek, T: ColorType, K: TiffKind> ImageEncoder<'a, W, T,
             strip_offsets: Vec::new(),
             strip_byte_count: Vec::new(),
             dropped: false,
+            compression: compression,
             _phantom: ::std::marker::PhantomData,
         })
     }
@@ -354,7 +411,6 @@ impl<'a, W: 'a + Write + Seek, T: ColorType, K: TiffKind> ImageEncoder<'a, W, T,
     where
         [T::Inner]: TiffValue,
     {
-        // TODO: Compression
         let samples = self.next_strip_sample_count();
         if u64::try_from(value.len())? != samples {
             return Err(io::Error::new(
@@ -364,9 +420,12 @@ impl<'a, W: 'a + Write + Seek, T: ColorType, K: TiffKind> ImageEncoder<'a, W, T,
             .into());
         }
 
+        // Write the (possible compressed) data to the encoder.
         let offset = self.encoder.write_data(value)?;
+        let byte_count = self.encoder.last_written() as usize;
+
         self.strip_offsets.push(K::convert_offset(offset)?);
-        self.strip_byte_count.push(value.bytes().try_into()?);
+        self.strip_byte_count.push(byte_count.try_into()?);
 
         self.strip_idx += 1;
         Ok(())
@@ -392,12 +451,19 @@ impl<'a, W: 'a + Write + Seek, T: ColorType, K: TiffKind> ImageEncoder<'a, W, T,
             )
             .into());
         }
+
+        self.encoder
+            .writer
+            .set_compression(self.compression.get_algorithm());
+
         let mut idx = 0;
         while self.next_strip_sample_count() > 0 {
             let sample_count = usize::try_from(self.next_strip_sample_count())?;
             self.write_strip(&data[idx..idx + sample_count])?;
             idx += sample_count;
         }
+
+        self.encoder.writer.reset_compression();
         self.finish()?;
         Ok(())
     }
@@ -475,7 +541,9 @@ impl<'a, W: 'a + Write + Seek, T: ColorType, K: TiffKind> ImageEncoder<'a, W, T,
     }
 }
 
-impl<'a, W: Write + Seek, C: ColorType, K: TiffKind> Drop for ImageEncoder<'a, W, C, K> {
+impl<'a, W: Write + Seek, C: ColorType, K: TiffKind, D: Compression> Drop
+    for ImageEncoder<'a, W, C, K, D>
+{
     fn drop(&mut self) {
         if !self.dropped {
             let _ = self.finish_internal();

src/encoder/tiff_value.rs

@@ -1,4 +1,4 @@
-use std::io::Write;
+use std::{borrow::Cow, io::Write, slice::from_ref};
 
 use crate::{bytecast, tags::Type, TiffError, TiffFormatError, TiffResult};
 
@@ -12,7 +12,18 @@ pub trait TiffValue {
     fn bytes(&self) -> usize {
         self.count() * usize::from(Self::BYTE_LEN)
     }
-    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()>;
+
+    /// 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] {
@@ -23,9 +34,8 @@ impl TiffValue for [u8] {
         self.len()
     }
 
-    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
-        writer.write_bytes(self)?;
-        Ok(())
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(self)
     }
 }
 
@@ -37,10 +47,8 @@ impl TiffValue for [i8] {
         self.len()
     }
 
-    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
-        let slice = bytecast::i8_as_ne_bytes(self);
-        writer.write_bytes(slice)?;
-        Ok(())
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::i8_as_ne_bytes(self))
     }
 }
 
@@ -52,10 +60,8 @@ impl TiffValue for [u16] {
         self.len()
     }
 
-    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
-        let slice = bytecast::u16_as_ne_bytes(self);
-        writer.write_bytes(slice)?;
-        Ok(())
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::u16_as_ne_bytes(self))
     }
 }
 
@@ -67,10 +73,8 @@ impl TiffValue for [i16] {
         self.len()
     }
 
-    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
-        let slice = bytecast::i16_as_ne_bytes(self);
-        writer.write_bytes(slice)?;
-        Ok(())
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::i16_as_ne_bytes(self))
     }
 }
 
@@ -82,10 +86,8 @@ impl TiffValue for [u32] {
         self.len()
     }
 
-    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
-        let slice = bytecast::u32_as_ne_bytes(self);
-        writer.write_bytes(slice)?;
-        Ok(())
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::u32_as_ne_bytes(self))
     }
 }
 
@@ -97,10 +99,8 @@ impl TiffValue for [i32] {
         self.len()
     }
 
-    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
-        let slice = bytecast::i32_as_ne_bytes(self);
-        writer.write_bytes(slice)?;
-        Ok(())
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::i32_as_ne_bytes(self))
     }
 }
 
@@ -112,10 +112,8 @@ impl TiffValue for [u64] {
         self.len()
     }
 
-    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
-        let slice = bytecast::u64_as_ne_bytes(self);
-        writer.write_bytes(slice)?;
-        Ok(())
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::u64_as_ne_bytes(self))
     }
 }
 
@@ -127,10 +125,8 @@ impl TiffValue for [i64] {
         self.len()
     }
 
-    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
-        let slice = bytecast::i64_as_ne_bytes(self);
-        writer.write_bytes(slice)?;
-        Ok(())
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::i64_as_ne_bytes(self))
     }
 }
 
@@ -142,11 +138,9 @@ impl TiffValue for [f32] {
         self.len()
     }
 
-    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
-        // We write using nativeedian so this sould be safe
-        let slice = bytecast::f32_as_ne_bytes(self);
-        writer.write_bytes(slice)?;
-        Ok(())
+    fn data(&self) -> Cow<[u8]> {
+        // We write using native endian so this should be safe
+        Cow::Borrowed(bytecast::f32_as_ne_bytes(self))
     }
 }
 
@@ -158,75 +152,9 @@ impl TiffValue for [f64] {
         self.len()
     }
 
-    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
-        // We write using nativeedian so this sould be safe
-        let slice = bytecast::f64_as_ne_bytes(self);
-        writer.write_bytes(slice)?;
-        Ok(())
-    }
-}
-
-impl TiffValue for [Ifd] {
-    const BYTE_LEN: u8 = 4;
-    const FIELD_TYPE: Type = Type::IFD;
-
-    fn count(&self) -> usize {
-        self.len()
-    }
-
-    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
-        for x in self {
-            x.write(writer)?;
-        }
-        Ok(())
-    }
-}
-
-impl TiffValue for [Ifd8] {
-    const BYTE_LEN: u8 = 8;
-    const FIELD_TYPE: Type = Type::IFD8;
-
-    fn count(&self) -> usize {
-        self.len()
-    }
-
-    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
-        for x in self {
-            x.write(writer)?;
-        }
-        Ok(())
-    }
-}
-
-impl TiffValue for [Rational] {
-    const BYTE_LEN: u8 = 8;
-    const FIELD_TYPE: Type = Type::RATIONAL;
-
-    fn count(&self) -> usize {
-        self.len()
-    }
-
-    fn write<W: Write>(&self, writer: &mut TiffWriter<W>) -> TiffResult<()> {
-        for x in self {
-            x.write(writer)?;
-        }
-        Ok(())
-    }
-}
-
-impl TiffValue for [SRational] {
-    const BYTE_LEN: u8 = 8;
-    const FIELD_TYPE: Type = Type::SRATIONAL;
-
-    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]> {
+        // We write using native endian so this should be safe
+        Cow::Borrowed(bytecast::f64_as_ne_bytes(self))
     }
 }
 
@@ -242,6 +170,10 @@ impl TiffValue for u8 {
         writer.write_u8(*self)?;
         Ok(())
     }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(from_ref(self))
+    }
 }
 
 impl TiffValue for i8 {
@@ -256,6 +188,10 @@ impl TiffValue for i8 {
         writer.write_i8(*self)?;
         Ok(())
     }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::i8_as_ne_bytes(from_ref(self)))
+    }
 }
 
 impl TiffValue for u16 {
@@ -270,6 +206,10 @@ impl TiffValue for u16 {
         writer.write_u16(*self)?;
         Ok(())
     }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::u16_as_ne_bytes(from_ref(self)))
+    }
 }
 
 impl TiffValue for i16 {
@@ -284,6 +224,10 @@ impl TiffValue for i16 {
         writer.write_i16(*self)?;
         Ok(())
     }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::i16_as_ne_bytes(from_ref(self)))
+    }
 }
 
 impl TiffValue for u32 {
@@ -298,6 +242,10 @@ impl TiffValue for u32 {
         writer.write_u32(*self)?;
         Ok(())
     }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::u32_as_ne_bytes(from_ref(self)))
+    }
 }
 
 impl TiffValue for i32 {
@@ -312,6 +260,10 @@ impl TiffValue for i32 {
         writer.write_i32(*self)?;
         Ok(())
     }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::i32_as_ne_bytes(from_ref(self)))
+    }
 }
 
 impl TiffValue for u64 {
@@ -326,6 +278,10 @@ impl TiffValue for u64 {
         writer.write_u64(*self)?;
         Ok(())
     }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::u64_as_ne_bytes(from_ref(self)))
+    }
 }
 
 impl TiffValue for i64 {
@@ -340,6 +296,10 @@ impl TiffValue for i64 {
         writer.write_i64(*self)?;
         Ok(())
     }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::i64_as_ne_bytes(from_ref(self)))
+    }
 }
 
 impl TiffValue for f32 {
@@ -354,6 +314,10 @@ impl TiffValue for f32 {
         writer.write_f32(*self)?;
         Ok(())
     }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::f32_as_ne_bytes(from_ref(self)))
+    }
 }
 
 impl TiffValue for f64 {
@@ -368,6 +332,10 @@ impl TiffValue for f64 {
         writer.write_f64(*self)?;
         Ok(())
     }
+
+    fn data(&self) -> Cow<[u8]> {
+        Cow::Borrowed(bytecast::f64_as_ne_bytes(from_ref(self)))
+    }
 }
 
 impl TiffValue for Ifd {
@@ -382,6 +350,10 @@ impl TiffValue for Ifd {
         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 {
@@ -396,6 +368,10 @@ impl TiffValue for Ifd8 {
         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 {
@@ -411,6 +387,14 @@ impl TiffValue for Rational {
         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 {
@@ -426,6 +410,14 @@ impl TiffValue for SRational {
         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 {
@@ -445,6 +437,17 @@ impl TiffValue for str {
             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 {
@@ -458,8 +461,45 @@ impl<'a, T: TiffValue + ?Sized> TiffValue for &'a T {
     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);

src/encoder/writer.rs

@@ -1,3 +1,4 @@
+use crate::encoder::compression::*;
 use crate::error::TiffResult;
 use std::io::{self, Seek, SeekFrom, Write};
 
@@ -42,87 +43,126 @@ pub fn write_bigtiff_header<W: Write>(writer: &mut TiffWriter<W>) -> TiffResult<
 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 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_all(&n.to_ne_bytes())?;
-        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_all(&n.to_ne_bytes())?;
-        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_all(&n.to_ne_bytes())?;
-        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_all(&n.to_ne_bytes())?;
-        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_all(&n.to_ne_bytes())?;
-        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_all(&n.to_ne_bytes())?;
-        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_all(&n.to_ne_bytes())?;
-        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.writer.write_all(&n.to_ne_bytes())?;
-        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_f32(&mut self, n: f32) -> Result<(), io::Error> {
-        self.writer.write_all(&u32::to_ne_bytes(n.to_bits()))?;
-        self.offset += 4;
+        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.writer.write_all(&u64::to_ne_bytes(n.to_bits()))?;
-        self.offset += 8;
+        self.byte_count = self
+            .compressor
+            .write_to(&mut self.writer, &u64::to_ne_bytes(n.to_bits()))?;
+        self.offset += self.byte_count;
 
         Ok(())
     }

src/error.rs

@@ -10,6 +10,8 @@ use crate::tags::{
 };
 use crate::ColorType;
 
+use crate::weezl::LzwError;
+
 /// Tiff error kinds.
 #[derive(Debug)]
 pub enum TiffError {
@@ -288,5 +290,15 @@ impl From<std::num::TryFromIntError> for TiffError {
     }
 }
 
+impl From<LzwError> for TiffError {
+    fn from(err: LzwError) -> TiffError {
+        match err {
+            LzwError::InvalidCode => TiffError::FormatError(TiffFormatError::Format(String::from(
+                "LZW compressed data corrupted",
+            ))),
+        }
+    }
+}
+
 /// Result of an image decoding/encoding process
 pub type TiffResult<T> = Result<T, TiffError>;

tests/encode_images_with_compression.rs

@@ -0,0 +1,157 @@
+extern crate tiff;
+
+use std::io::{Cursor, Seek, Write};
+use tiff::{
+    decoder::{Decoder, DecodingResult},
+    encoder::{
+        colortype::{self, ColorType},
+        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<C: Compression, W: Write + Seek>(
+        &self,
+        encoder: &mut TiffEncoder<W>,
+        compression: C,
+    ) where
+        [<Self::Color as ColorType>::Inner]: TiffValue,
+    {
+        let image = encoder
+            .new_image_with_compression::<Self::Color, C>(Self::WIDTH, Self::HEIGHT, compression)
+            .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<C: Compression + Clone>(compression: C) {
+    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();
+        image_rgb.compress(&mut encoder, compression.clone());
+        image_grayscale.compress(&mut encoder, compression);
+    }
+
+    // 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(Uncompressed::default());
+}
+
+#[test]
+fn encode_decode_with_lzw() {
+    encode_decode_with_compression(Lzw::default());
+}
+
+#[test]
+fn encode_decode_with_deflate() {
+    encode_decode_with_compression(Deflate::with_level(DeflateLevel::Fast));
+    encode_decode_with_compression(Deflate::with_level(DeflateLevel::Balanced));
+    encode_decode_with_compression(Deflate::with_level(DeflateLevel::Best));
+}
+
+#[test]
+fn encode_decode_with_packbits() {
+    encode_decode_with_compression(Packbits::default());
+}