Update y/x coords for mirror-flip TIFF orientations (#1537)#1539
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brendancol wants to merge 2 commits intomainfrom
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Update y/x coords for mirror-flip TIFF orientations (#1537)#1539brendancol wants to merge 2 commits intomainfrom
brendancol wants to merge 2 commits intomainfrom
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Orientations 2/3/4 in the TIFF Orientation tag (274) flip the array horizontally, both axes, or vertically. PR #1521 applied the buffer remap but left the y/x coord arrays computed from the un-flipped transform, so xarray label lookups against a georeferenced file returned the wrong pixel under any of those orientations. The fix updates the geo_info transform after the array remap so a displayed pixel and its geographic label point to the same location on the ground. PixelIsArea and PixelIsPoint both work; the unrotated transform is still preserved for ungeoreferenced files (coords stay on integer pixel indices).
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Summary
read_to_arrayso xarray label lookups land on the right pixel for georeferenced files.N * step) and PixelIsPoint (shifts by(N-1) * step).Context
PR #1521 added the buffer remap for the Orientation tag (274). The 5-8 axis-swap branch already updates the transform (and warns). The 2/3/4 mirror branch was never wired up, so
_reader.pyflipped the array but kept the un-flipped origin and pixel-scale signs.da.sel(x=..., y=...)against the result returned whatever pixel originally lived at those coords -- not the pixel actually displayed there. See #1537 for a full reproducer.Test plan
pytest xrspatial/geotiff/tests/test_orientation.py -q(was 36, now 46 -- new tests cover sel-fidelity for orient 2/3/4 under PixelIsArea and PixelIsPoint, the coord-array first-element values, and the no-georef passthrough).pytest xrspatial/geotiff/tests/ -q --no-header --deselect xrspatial/geotiff/tests/test_features.py::TestPalette(942 passed; the deselected test failures are unrelated -- a Python 3.14 / matplotlib deepcopy regression).pytest xrspatial/geotiff/tests/test_planar_multiband.py xrspatial/geotiff/tests/test_lerc_valid_mask_gpu.py xrspatial/geotiff/tests/test_predictor2_big_endian_gpu_1517.py xrspatial/geotiff/tests/test_gpu_byteswap_1508.py xrspatial/geotiff/tests/test_gpu_strict_fallback_1516.py xrspatial/geotiff/tests/test_gpu_stripped_multiband.py -q(91 passed; CPU-only change, GPU path unaffected).Closes #1537.