UI/jpeg exif orientation#24196
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ServeurpersoCom merged 3 commits intoJun 12, 2026
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stb_image in mtmd ignores exif metadata, so rotated smartphone photos reach the model with raw pixel orientation. The webui now reads the exif orientation tag at send time and feeds it into the existing capImageDataURLSize canvas pass: the browser applies the rotation when decoding, so capped images come out upright for free, and images under the cap threshold get a single plain redraw when orientation > 1. At most one re-encode ever happens per image. Upright jpegs with capping disabled pass through untouched, bit perfect. Adds jpeg-orientation.ts with a minimal exif parser working on a bounded base64 prefix (both endianness, returns 1 on any malformed input) and unit tests against handcrafted jpeg byte streams.
Covers capImageDataURLSize end to end in chromium with real Pillow generated jpeg fixtures across exif orientations 1/3/5/6/8: upright quadrant colors checked pixel-wise, expected dimensions with and without capping, no orientation tag left in the output, and strict passthrough when nothing needs rewriting.
allozaur
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ggerganov
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UI/jpeg exif orientation (ggml-org#24196)
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Overview
stb_image in mtmd ignores EXIF, so rotated smartphone photos reach the model sideways. The webui now reads the orientation tag at send time and bakes the rotation through the existing capImageDataURLSize canvas pass. At most one re-encode per image: capped images come out upright for free, uncapped rotated ones get a single redraw, everything else passes through untouched.
Additional information
Tested across orientations 1/3/5/6/8 with Qwen3.6 VLM, with and without resize.
Unit test covers the EXIF parser against synthetic JPEGs (both endiannesses, malformed inputs). Browser test covers capImageDataURLSize end to end in chromium with real fixtures: upright pixels, expected dimensions, strict passthrough when nothing needs rewriting.
Closes #20870
Prompt for manual E2E tests: "Which color is the top edge, and which direction does the arrow point?"
Manuals-E2E-Tests.zip
Expected answer for all images: red / up.
Requirements