On Thu, 2 Jan 2025 06:49:19 GMT, Jeremy <d...@openjdk.org> wrote: >> This adds support for parsing thumbnails in an APP1 Exif marker. >> >> This builds on an unfinished proposal by Brian Burkhalter (around 2016). In >> that previous work the only additional meta info he parsed was the image >> creation time; this PR similarly includes the same property. (I can't speak >> to why he included that property, but it looks like he has a lot of >> experience with ImageIO so I trust his judgment.) >> >> The test addresses the original images attached to the ticket plus a few >> extra images I found on my computer that include unusual properties. >> (Possibly those images are malformed, but if they exist in the wild and >> other platforms support them then I'd prefer to support them too.) > > Jeremy has updated the pull request incrementally with one additional commit > since the last revision: > > 8160327: fixing typo so `thumbnailPos` can be zero > > The `thumbnailLength` cannot be zero, but the position can be.
For test image preparation, [exiftool](https://exiftool.org/) might prove useful. For example, to extract a thumbnail from an Exif image: `exiftool -b -ThumbnailImage image.jpg > thumb.jpg` To embed a thumbnail: `exiftool "-thumbnailimage<=thumb.jpg" image.jpg` Unfortunately, it refuses to embed a PNG thumbnail in a file where the primary image is compressed, which would be useful to generate an Exif sample with a compressed primary image but an uncompressed thumbnail. ------------- PR Comment: https://git.openjdk.org/jdk/pull/22898#issuecomment-2659948576
