Move nested conditions into match guards and simplify equivalent Boolean
expressions without changing validation or short-circuit behavior. Keep
the explicit permitted Testkit dev-dependency arm in the layer checker.
Co-Authored-By: OpenAI Codex <noreply@openai.com>
`header` accepts a lossless frame but the decoder routing only sent
CMYK/cropped/12-bit/non-interleaved files to jpeg-decoder: an 8-bit SOF3
file went to zune-jpeg, which refuses lossless, so a listed file could not
open at all. The files that did reach jpeg-decoder were wrong too:
jpeg-decoder emits its lossless samples native-endian (its `to_ne_bytes`),
so `from_be_bytes` swapped every sample (a 12-bit 2048 decoded as 8), the
raw `precision`-bit value was never left-justified into the 16-bit range
`Buf::U16` feeds onward, and a 3- or 4-component frame over 8 bits still
reports `RGB24`/`CMYK32` while holding two bytes per sample, so it was
wrapped as 8-bit data over double-length rows. `scale()` (a DCT size, not
a lossless resample) also cut a lossless frame to the top-left when a
thumbnail box was requested.
Every SOF3 file now routes to jpeg-decoder; lossless frames skip `scale`
(`finish` scales after); lossless samples are read native-endian and
left-justified; high-precision RGB/CMYK become `Buf::U16`.
Four hand-built SOF3 regression tests (12-bit gray, 12-bit RGB, 12-bit
CMYK, and 8-bit through the public `decode`); all four fail before the fix
(byte-swapped samples, U8-wrapped high-precision buffers, and the zune
refusal) and pass after. The crate's other tests stay green.
`lightcraft_codecs::gainmap`:
- `compute` measures a gain map (luminance or RGB, log2, block-averaged)
from an SDR and an HDR rendition; `apply` rebuilds the HDR rendition.
- ISO 21496-1 metadata: writer (fixed denominator) and reader (also the
common-denominator form; refuses unknown versions, backward maps and zero
denominators). Adobe `hdrgm` XMP reader and writer, per-channel values as
rdf:Seq; Apple's HDRGainMap/HDRToneMap description of the same map.
- `encode_jpeg`: base with CIPA DC-007 MPF index (gain map typed 0x050000),
the ISO marker and Container XMP merged into the user's packet, followed by
the gain map JPEG. `read_jpeg` / `is_gain_map_jpeg` find and decode the map.
Also: gain map images are no longer picked as embedded thumbnails (an Ultra
HDR JPEG could show its greyscale gain map in the grid). The JPEG APP-segment
building is shared with `encode_jpeg`. Fuzzed with the other decoders.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A full-size load asks the decoder for the largest box (`SourceLevel::Full` is
`usize::MAX`, cast to `u32::MAX`). `jpeg::decode` then computed `2 * u32::MAX` to
decide on DCT scaling: an overflow panic in debug builds (caught, so every
full-size JPEG load failed with "decoder panicked"), and a wrap that happened to
give the right answer in release. The comparison saturates now, and the engine
converts its `usize` edge with `u32::try_from` instead of a truncating `as`.
Found decoding camera JPEGs (no JFIF/EXIF header) at full size.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The import probe of a non-raw image decoded it (at a 64 px fit, which for
JPEG still entropy-decodes every block and for PNG inflates everything)
only to learn its stored size and orientation: ~95 % of import CPU.
lightcraft-codecs gets `read_header(bytes) -> Header { format, width,
height, orientation }`: JPEG from its markers (EXIF orientation), PNG from
its chunks (IHDR, eXIf anywhere), TIFF from the first IFD (tiff crate,
no strips read), WebP from its RIFF chunks / bitstream header (image-webp),
PSD from its header and image resources. GIF, BMP and JPEG XL keep the
small decode. `files::probe_bytes` uses it; raw handling is unchanged.
The TIFF colour-layout check is shared with the decoder (`layout`).
Measured (release, 4 cores, throwaway benchmark, per file, bytes in
memory): 200 generated 4000x3000 JPEGs (3.6 MB): 72.7 ms -> 2.1 ms
(read_header alone 1.05 ms; the rest is the content hash and metadata);
20 PNGs (30.8 MB): 236-265 ms -> 9.0-9.6 ms.
Corrupt files (behaviour note): the header readers also refuse what a
decode refuses before the pixels (unsupported layout, compression, frame
type, bad IHDR, ...) and truncated files: a JPEG whose markers don't reach
its EOI, a PNG cut before the chunk after its IDAT run, TIFF strips/tiles
that start past the end, a WebP image chunk or PSD merged data past the
end. So truncated files (interrupted copies, partial downloads) are still
marked `error` in the import review, as before; tests check that whenever
the old decode accepted a (cut or byte-mutated) file the header agrees.
Changed: damage *inside* compressed data that is all present (flipped or
garbled bytes) was refused at scan and is now imported, and shows as
unreadable ("!" in the grid) when rendered. Also: tiny JPEGs (< 128 px)
were decoded leniently by the old probe, so a truncated one imported; it
is now refused. A TIFF truncated inside its last strip is not detected
(StripByteCounts are often overstated, so only strip starts are checked).
Tests: header readers vs decode on generated JPEG/PNG/TIFF/WebP/PSD/BMP
with and without EXIF/TIFF orientation; truncations and random mutations
agree with decode; hostile headers (zero/absurd sizes, bad lengths,
truncation, garbage) are errors; read_header added to the fuzz tests;
probe_bytes oriented dims match the decode-based values.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01912WaK6Rmew3wxZuPyX7E8
Rust 1.99 (stable since 2026-09-28) adds clippy::chunks_exact_to_as_chunks and widens
clippy::question_mark, which failed `cargo xtask ci` on main. Same behaviour: the
remainder that chunks_exact skipped is the remainder as_chunks returns separately.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Property tests (random bytes behind every magic, mutated/truncated files),
corpus tests (corpus/images, pngsuite, raw routing, system ICC profiles),
ignored 24 MP JPEG benchmark, decode_thumbnail_with(min_embedded_edge),
fast deflate levels for PNG/TIFF, README with formats, licences, gaps.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Decoders (JPEG via zune-jpeg + jpeg-decoder for DCT scaling/CMYK, PNG,
TIFF, WebP, GIF, BMP, PSD composite, JPEG XL via jxl-oxide) produce linear
Rgb32f in source primaries with SourceSpace; ICC matrix/TRC applied exactly,
LUT/CMYK profiles through moxcms; to_working() to linear Rec.2020 D65.
Encoders: JPEG, PNG 8/16, TIFF 8/16/32f, lossless WebP, AVIF (native).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Brandon Thomas