Four CC0 EOS RP samples from raw.pixls.us (lossless RAW and C-RAW, full
frame and 1.6x crop mode) now have exact full-sensor regressions against
the DNGLab 0.8.0 black-box oracle (Windows binary, checked first against
the documented M50 RAW hash). The decoder already matched; no decoder
change was needed. Crop mode is a single 4032x2656 tile, full frame two
3192-wide tiles.
docs/cr3.md also records that the white level is Canon's specular white,
which at the -1/3-stop ISOs (e.g. 11062 at ISO 5000) is well below the
sensor's saturation point.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Version 66 keeps version 64's as-shot white balance and black level
offsets; its word 661 is below where the sensor clips, so the white
level stays measured from the data. Checked on 33 R6 Mark III files
from 12 shoots: all now open with their as-shot white balance, black
levels match the masked columns.
Co-Authored-By: Claude <[email protected]>
Claude-Session: https://claude.ai/code/session_017JKdR4oZ3jRSPPwMLLTa2U
The CRX 0x200 QP map opens with its first symbol as a 32-bit literal; every
later symbol is Rice coded with a limited-length escape: 23 zeros, the
terminating 1 and the symbol in 8 bits (the ITU-T T.87 layout for a 32-bit
limit and 8-bit symbols, without its minus-one offset). The old rule (an
escape after 16 zeros with a 16-bit literal) matched only the first symbol,
which is all the R8 and R7 maps need. R5 Mark II maps (QP 150-162) jump by up
to 12 where the Rice parameter is 0, giving 18- to 22-zero prefixes that
misparsed ("Canon CRX adaptive QP value -21087"): 174 of 306 sampled files
from a private R5 Mark II library opened as previews. Every QP map of its
33,665 C-RAW files now decodes to the exact end of its entropy stream; the six
oracle fixtures are unchanged. Established by black-box analysis of the
bitstream; no third-party decoder source consulted.
Adds the four CC0 R5 Mark II samples (raw.pixls.us 7881-7884) to the corpus
with pinned sensor hashes (the crop-mode framing is left to #754), bumps
RENDER_CACHE_VERSION to 43, and updates cr3.md, raw-parity (235 verified
models), coverage, gaps, the checklist rows, ROADMAP, target-app-parity and
What's New.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Canon EOS R50 C-RAW files reach QP 168 (quant 44, step 102, measured about 100). The quantization step and the adaptive QP map range accept it; anything above stays rejected. Bumps RENDER_CACHE_VERSION since such files change from the embedded preview to a raw decode.
The R5 Mark II's APS-C crop-mode files (5376 x 3574) state an IAD1 active area of x 132..5243,
but columns 132..~256 sit at the black level and the image runs to the right edge (measured on
raw.pixls.us 7883/7884), while their recommended crop, x 272..5359 (5088 x 3392, the camera JPEG's
size), lies on the image. The recommended crop didn't fit inside the stated active area, so the
whole active area was kept: a black band down the left and ~130 image columns lost.
When the recommended crop doesn't fit inside the stated active area, it is now the valid area.
On 7883 the render's high-pass correlation with the camera JPEG goes from -0.13 to 0.99. The
active area and crop of the other 108 decodable CC0 CR3s on raw.pixls.us are unchanged.
RENDER_CACHE_VERSION 49.
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) <[email protected]>
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