The Bayer layout of Canon CR2 files differs by model (GBRG on the 7D, 50D,
60D, 550D, 600D, 1200D, 1300D, 5D Mark II, 1D Mark IV; RGGB on the 40D,
5D Mark III, 6D, 5DS R and others). Read it from raw IFD tag 0xc5e0
(CR2CFAPattern: 1 RGGB, 2 BGGR, 3 GBRG, 4 GRBG), anchored at the full
decoded sensor; fall back to RGGB when the tag is missing. No model table.
Checked on 35 decoded CC0 raw.pixls.us CR2s (35 models): the tag agrees
with the mosaic's green-diagonal statistic on every file; the SensorInfo
border parity does not predict the layout. Corpus manifest gains the
reporter's samples; a corpus test asserts each layout.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>