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Ok, people seem upset about this off by default support being removed. What is it that makes jpegxl valuable given that there’s already widespread adoption and

by olliej 4y ago

Ok, people seem upset about this off by default support being removed. What is it that makes jpegxl valuable given that there’s already widespread adoption and support for av1, webp, etc? Baring in mind that turning on jpegxl means exposing yet another image format parser to the web and the security track record of image formats has not been stellar.

xeeeeeeeeeeenu 4y ago
>What is it that makes jpegxl valuable given that there’s already widespread adoption and support for av1, webp, etc? IMO the killer feature of JPEG XL is its ability to losslessly transcode already existing JPEG images. See also these articles for a more detailed comparison: https://cloudinary.com/blog/how_jpeg_xl_compares_to_other_image_codecs https://cloudinary.com/blog/how_jpeg_xl_compares_to_other_im... https://cloudinary.com/blog/time_for_next_gen_codecs_to_dethrone_jpeg https://cloudinary.com/blog/time_for_next_gen_codecs_to_deth... (disclaimer: they were written by one of the authors of JPEG XL)
- chungy 4y ago
  > IMO the killer feature of JPEG XL is its ability to losslessly transcode already existing JPEG images. It's a nice transitory feature, but I think improved progressive decoding is even more worthwhile.
- olliej 4y ago
  Lossless transcoding is not a selling point IMO. It’s not relevant for new images (new devices aren’t producing jpegs), and I just don’t see people mass re-encoding their photo libraries. Features that actually matter to normal users are what is important. In that area progressive display seems like it would arguably be more useful, though I think it would still be dependent on what the image size is - websites now routinely require megs of JS to display anything at all, because net speeds are now fast enough that huge amounts of data are needed to get to a “noticeable” latency that would warrant display of incomplete data.
Dwedit 4y ago
Just did a quick test comparing WEBP and JXL when saved at a file size equivalent to JPEG quality 90. WEBP has blurry chroma, looking like it's subsampled then upscaled. The chroma on JPEG-XL is trying to be full resolution, and if you look at the chroma in isolation, it looks a bit blocky, but it's not blurry at all.
- olliej 4y ago
  How do heif/heic/av1 compare (I no longer understand whether we’re referring to codec or extension :) )?
twotwotwo 4y ago
Apart from numerical or visual comparisons, it does things other formats don't: https://news.ycombinator.com/item?id=27581195 https://news.ycombinator.com/item?id=27581195 The lossless recompression of existing .jpg content and faster software encoding for its native VarDCT format seem to provide immediate benefits in contexts where AVIF doesn't fit well now, either because AVIF encoding is slow or because AVIF would require a lossy reencoding of a lossily compressed source.

by olliej 4y ago

xeeeeeeeeeeenu 4y ago

>What is it that makes jpegxl valuable given that there’s already widespread adoption and support for av1, webp, etc? IMO the killer feature of JPEG XL is its ability to losslessly transcode already existing JPEG images. See also these articles for a more detailed comparison: https://cloudinary.com/blog/how_jpeg_xl_compares_to_other_image_codecs https://cloudinary.com/blog/how_jpeg_xl_compares_to_other_im... https://cloudinary.com/blog/time_for_next_gen_codecs_to_dethrone_jpeg https://cloudinary.com/blog/time_for_next_gen_codecs_to_deth... (disclaimer: they were written by one of the authors of JPEG XL)

chungy 4y ago
> IMO the killer feature of JPEG XL is its ability to losslessly transcode already existing JPEG images. It's a nice transitory feature, but I think improved progressive decoding is even more worthwhile.
olliej 4y ago
Lossless transcoding is not a selling point IMO. It’s not relevant for new images (new devices aren’t producing jpegs), and I just don’t see people mass re-encoding their photo libraries. Features that actually matter to normal users are what is important. In that area progressive display seems like it would arguably be more useful, though I think it would still be dependent on what the image size is - websites now routinely require megs of JS to display anything at all, because net speeds are now fast enough that huge amounts of data are needed to get to a “noticeable” latency that would warrant display of incomplete data.

Dwedit 4y ago

Just did a quick test comparing WEBP and JXL when saved at a file size equivalent to JPEG quality 90. WEBP has blurry chroma, looking like it's subsampled then upscaled. The chroma on JPEG-XL is trying to be full resolution, and if you look at the chroma in isolation, it looks a bit blocky, but it's not blurry at all.

olliej 4y ago
How do heif/heic/av1 compare (I no longer understand whether we’re referring to codec or extension :) )?

twotwotwo 4y ago

Apart from numerical or visual comparisons, it does things other formats don't: https://news.ycombinator.com/item?id=27581195 https://news.ycombinator.com/item?id=27581195 The lossless recompression of existing .jpg content and faster software encoding for its native VarDCT format seem to provide immediate benefits in contexts where AVIF doesn't fit well now, either because AVIF encoding is slow or because AVIF would require a lossy reencoding of a lossily compressed source.