An odd-height adaptive QP map (EOS R7: 4732 sensor rows, 1183 QP rows)
was rejected as unsupported, so R7 C-RAW files opened from their embedded
JPEG. The map decodes to the exact end of its entropy stream; the last
row of the second-level high-frequency bands has no partner row and its
QP is used alone. Even-height maps never reach this rule, so the six
verified M50/R100/R8 fixtures are unchanged.
Checked on paired R7 RAW and C-RAW captures (ISO 100 and 6400): all
six C-RAW files decode, developed images match their RAW counterparts
visually, and ISO 6400 sensor means agree within 0.1%.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Gs6roPby7THvteijZwptQt
The Canon maker note's AspectInfo (tag 0x009a: aspect code, cropped width,
height, left, top) holds the rectangle of the shot, measured from the
recommended image crop. Use it as the CR3 default crop, so 3:2, 4:3, 16:9 and
1:1 shots develop in the shape the photographer chose. The tag is ignored when
it is missing, does not fit, or the recommended crop itself is inconsistent.
RENDER_CACHE_VERSION 15 -> 16. The M50 C-RAW corpus sample (raw.pixls.us 2663)
was shot at 1:1 and now develops at 4000 x 4000.
C-RAW is quantised wavelet coding: next to clipped highlights its
reconstruction overshoots the sensor range by a few quantisation steps.
On 17 CC0 CR3 files (SX70 HS, G5 X Mark II, M6 Mark II, EOS R, RP, 90D,
M200, R5 Mark II, R6 Mark II, R6 Mark III, R8) samples reached 16384 to
16419 at 14 bits, never below 0, and decoding failed with "decoded
sample outside its bit depth". Lossless files of the same bodies clip at
exactly 16383. Wavelet samples are now clamped to the CMP1 bit depth;
lossless samples outside it are still corrupt data.
The other 93 CR3 files have no sample outside the range and render
pixel-identically. Render cache version 13 -> 14.
Decode lossless CRX and version 0x100/0x200 C-RAW in portable Rust,
including sensor geometry, timed white balance and black/white levels.
Verify all sensor samples against six independent M50/R100/R8 references.
Any CR3 decode error falls back to the embedded JPEG, as CR3 files did
before this decoder. The full sensor buffer is allocated only after the
first plane decodes, and plane buffers grow row by row. Tile planes
decode in parallel with a windowed bit reader (24 MP: 424 -> 89 ms
lossless, 519 -> 138 ms C-RAW on an M4).
Add guarded CR3 camera-JPEG colour fitting with independent framing
validation, relative white balance and cache invalidation.
Validation: cargo xtask ci.
Brandon Thomas
Claude
radialmonster
Иван Лапочкин