Lilith River
83409cbdf3
Add YCbCrUpsamplingReader that converts chroma-subsampled YCbCr block data to full-resolution 3-bytes-per-pixel output. Each block of h×v pixels stores h*v Y samples plus one shared Cb and Cr sample; the reader expands these into per-pixel (Y, Cb, Cr) triples. This enables decoding YCbCr TIFFs with any supported compression method (uncompressed, LZW, Deflate, etc.), not just JPEG. Two more libtiffpic test images now decode with verified hashes: - dscf0013.tif (uncompressed YCbCr 2,1 subsampling) - ycbcr-cat.tif (LZW-compressed YCbCr 2,2 subsampling) The remaining two YCbCr test images (smallliz.tif, zackthecat.tif) use Old JPEG compression (type 6) which is a separate unsupported feature.
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.