Reject mixed BitsPerSample per band in TIFF readers#1519
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brendancol wants to merge 1 commit intoxarray-contrib:mainfrom
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Reject mixed BitsPerSample per band in TIFF readers#1519brendancol wants to merge 1 commit intoxarray-contrib:mainfrom
brendancol wants to merge 1 commit intoxarray-contrib:mainfrom
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A TIFF whose BitsPerSample tag holds a different value per band (e.g. (16, 16, 16, 8) for RGB plus an 8-bit alpha) was silently decoded with the first band's width applied to every band, so the mismatched bands came back as garbage. The fix adds a _dtypes.resolve_bits_per_sample(bps) helper and threads every reader site through it: stripped CPU, tiled CPU, GPU, VRT, the geo-info probe, and the palette colormap path. The helper accepts a scalar or a tuple/list whose entries all agree, and raises ValueError with the mixed values and a gdal_translate hint when they don't. Closes xarray-contrib#1505
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Closes #1505
A TIFF whose
BitsPerSampletag holds a different value per band (e.g.(16, 16, 16, 8)for RGB plus an 8-bit alpha) was silently decoded with the first band's width applied to every band, so the mismatched bands came back as garbage.The fix adds a
_dtypes.resolve_bits_per_sample(bps)helper and threads every reader site through it: stripped CPU, tiled CPU, GPU, VRT, the geo-info probe, and the palette colormap path. The helper accepts a scalar or a tuple/list whose entries all agree, and raisesValueErrorwith the mixed values and agdal_translatehint when they don't.Decoding each band separately and promoting to a common dtype was the alternative; it's more code for a rare case, and silent promotion raises follow-up questions (whose nodata wins, what does the user actually want). An explicit error lets the user convert with GDAL or rasterio.
Test plan
pytest xrspatial/geotiff/tests/test_mixed_bps.py-- 9 new tests: the helper plus an end-to-end RGB+8-bit-alpha file built from raw IFD bytespytest xrspatial/geotiff/tests/-- 699 passed; 3 pre-existing matplotlib palette failures are unrelated