Lilith River
3d3c16e26f
TIFF files can store samples at non-standard bit depths (e.g. 10, 12, 14, 24 bits) packed tightly in a continuous bit stream. Previously these were rejected as unsupported color types. This adds: - MSB-first bit extraction from packed byte streams (unpack_bits, extract_bits_msb) to expand N-bit samples to standard-width output (9-16 bit → u16, 17-32 bit → u32) - Output buffer sizing using the promoted sample width instead of the packed bit depth (output_bits_per_sample field in ReadoutLayout) - A new code path in expand_chunk that reads packed rows, unpacks to standard-width samples, then applies predictor and color inversion - Horizontal predictor support for extended depths Tested with 12-bit grayscale and RGB images (existing test suite), plus all libtiffpic depth test images (10/12/14/24-bit in gray, RGB contig, and RGB planar configurations).
image-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 | ✓ | ✓ |
| Fax4 | ✓ | not yet |
| 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 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.