vision_analyze rejected iPhone photos with 'source is not a recognized
image'. iPhones capture HEIC (ISO-BMFF/HEVC) and upload pipelines often
mislabel it .jpg; the magic-byte sniff had no HEIF branch, so the bytes
were rejected before reaching normalization.
- _detect_image_mime_type_from_bytes: sniff the ISO-BMFF 'ftyp' box and
recognize HEIF/HEIC (heic/heix/heim/heis/hevc/hevx/mif1/msf1) and AVIF
(avif/avis) brands, returning image/heic or image/avif. Non-image ftyp
brands (mp4, ...) stay unrecognized.
- _normalize_to_supported_image: register the pillow-heif Pillow opener,
then re-encode HEIF/AVIF to PNG before embed (same soft-dependency
pattern as SVG rasterization). Missing decoder yields an actionable
'pip install pillow-heif' error, not a generic failure.
- Add pillow-heif==1.4.0 as a core dep alongside Pillow (prebuilt wheels
bundle libheif; no system libs needed).
- Tests: brand detection (incl. AVIF + mp4-not-misdetected), end-to-end
HEIC->PNG normalization, and the decoder-missing error path.
The vision resolver's magic-byte sniff stays authoritative (no extension
trust); HEIF now reaches the existing normalize step instead of 400ing.
Samuel Painter