5 ms·

Also features like alpha support, yuv444 support in addition to yuv420, progressive rendering are interesting. Do jxl and avif both have all of these?

by bla3 3y ago

krasin 3y ago
Also 16-bit colors support! The fact that AVIF does not have it is a bummer (although, understandable given the fact AVIF is for a video codec, not for editing HDR images).
- jdiff 3y ago
  Honestly that plus the awful tiling behavior at relatively low resolutions should have been enough to disqualify it from being mangled into something resembling an image format. It was made and tuned for movies, not stills. But its image format gets to inherit all of the drawbacks of that initial use case, including awful encode/decode performance.
- cubefox 3y ago
  Wait, after decades they are introducing a new image format, and it doesn't even have HDR support?! But surely AV1 supports HDR, so why not AVIF? Edit: According to this table, AVIF does in fact support HDR: https://jpegxl.info/ https://jpegxl.info/
  - krasin 3y ago
    AVIF supports "8-, 10-, and 12-bit color depths". It does not support 16-bit color depths (which is my claim made in the comment above). See https://en.wikipedia.org/wiki/AVIF https://en.wikipedia.org/wiki/AVIF The need for 16-bit colors arises when HDR content is edited, but unnecessary for just playback. AVIF is a playback format, so they didn't feel the need to support 16-bit colors, I guess.
    - cubefox 3y ago
      I think a bigger issue is that it apparently doesn't support images exceeding just 9 megapixels, making it unsuitable even for digital photography today. There is a technique of stitching multiple images together, but I'm not sure what other drawbacks this has. Another problem is that it doesn't support progressive loading in the browser. Meaning the AVIF image only shows when it is fully loaded: https://www.youtube.com/watch?v=UphN1_7nP8U&feature=youtu.be https://www.youtube.com/watch?v=UphN1_7nP8U&feature=youtu.be That looks really bad for the web and could make AVIF subjectively slower than most other image formats. It's disappointing. There is a once-in-multiple-decades chance to establish a big new image format -- and then it doesn't even support some basic features JPEG had decades ago. If AVIF wins, we probably would have to live with its problems for ages. It reminds of JPEG not supporting an alpha channel. 30 years later this blunder still causes headaches. So yeah, AVIF seems to have better compression than JPEG XL, if the subjective examples are reliable, but at least the latter doesn't miss basic features, which seems more important in the long run. Alas, Google/Chrome favors AVIF, so JPEG XL seems doomed.
vanderZwan 3y ago
There's a neat table on https://jpegxl.info/ https://jpegxl.info/ which shows all features of both formats. In general JXL has more features than AVIF, although some of them may be more important for special purposes like medical imaging.
- iLoveOncall 3y ago
  And I'm sure we can expect a perfectly unbiased opinion regarding the matter from jpegxl.info.
  - vanderZwan 3y ago
    In which world are technical features like "how many channels the format supports" or "maximum bit depth" or "progressive decoding" opinions, exactly?
    - jdiff 3y ago
      You can pick and choose which facts to present or misrepresent which/what is important but... that's not going on here. JXL is actually just better by very many metrics. It's only lacking in adoption. There's not something that jpeg-xl.info is ignoring or glossing over. This is just lazy cynicism.
    - iLoveOncall 3y ago
      I was mostly joking, but you can compare a skateboard and a car and make the skateboard look better if you just mention weight and pollution but not top speed, autonomy, etc.
      - vanderZwan 3y ago
        Well, ok, that's a fair point: from this table alone you can't say anything about computational complexity or implementation difficulty. And I cannot honestly say anything about that. I agree that it's a valid question to ask. I'm afraid that your first reply misfired a bit if that was what you wanted to get across though.
JyrkiAlakuijala 3y ago
AVIF has progressive support in the spec, but it has not yet been implemented in an encoder and it is very likely going to be less dense than the non-progressive coding. My guesswork is that it will be ~10 % less dense than non-progressive once implemented, but it is just a guess with my pass experiences of other codec experiments trying to do such things. Otherwise both formats have all features. JPEG XL is yuv444 by default whereas AVIF tends to favor yuv420 and some encoding/decoding hardware is going to be yuv420 only, so with AVIF one would often need to go software coding to get yuv444 quality.

Also features like alpha support, yuv444 support in addition to yuv420, progressive rendering are interesting. Do jxl and avif both have all of these?

by bla3 3y ago

Also features like alpha support, yuv444 support in addition to yuv420, progressive rendering are interesting. Do jxl and avif both have all of these?

krasin 3y ago

Also 16-bit colors support! The fact that AVIF does not have it is a bummer (although, understandable given the fact AVIF is for a video codec, not for editing HDR images).

jdiff 3y ago
Honestly that plus the awful tiling behavior at relatively low resolutions should have been enough to disqualify it from being mangled into something resembling an image format. It was made and tuned for movies, not stills. But its image format gets to inherit all of the drawbacks of that initial use case, including awful encode/decode performance.
cubefox 3y ago
Wait, after decades they are introducing a new image format, and it doesn't even have HDR support?! But surely AV1 supports HDR, so why not AVIF? Edit: According to this table, AVIF does in fact support HDR: https://jpegxl.info/ https://jpegxl.info/
- krasin 3y ago
  AVIF supports "8-, 10-, and 12-bit color depths". It does not support 16-bit color depths (which is my claim made in the comment above). See https://en.wikipedia.org/wiki/AVIF https://en.wikipedia.org/wiki/AVIF The need for 16-bit colors arises when HDR content is edited, but unnecessary for just playback. AVIF is a playback format, so they didn't feel the need to support 16-bit colors, I guess.
  - cubefox 3y ago
    I think a bigger issue is that it apparently doesn't support images exceeding just 9 megapixels, making it unsuitable even for digital photography today. There is a technique of stitching multiple images together, but I'm not sure what other drawbacks this has. Another problem is that it doesn't support progressive loading in the browser. Meaning the AVIF image only shows when it is fully loaded: https://www.youtube.com/watch?v=UphN1_7nP8U&feature=youtu.be https://www.youtube.com/watch?v=UphN1_7nP8U&feature=youtu.be That looks really bad for the web and could make AVIF subjectively slower than most other image formats. It's disappointing. There is a once-in-multiple-decades chance to establish a big new image format -- and then it doesn't even support some basic features JPEG had decades ago. If AVIF wins, we probably would have to live with its problems for ages. It reminds of JPEG not supporting an alpha channel. 30 years later this blunder still causes headaches. So yeah, AVIF seems to have better compression than JPEG XL, if the subjective examples are reliable, but at least the latter doesn't miss basic features, which seems more important in the long run. Alas, Google/Chrome favors AVIF, so JPEG XL seems doomed.

vanderZwan 3y ago

There's a neat table on https://jpegxl.info/ https://jpegxl.info/ which shows all features of both formats. In general JXL has more features than AVIF, although some of them may be more important for special purposes like medical imaging.

iLoveOncall 3y ago
And I'm sure we can expect a perfectly unbiased opinion regarding the matter from jpegxl.info.
- vanderZwan 3y ago
  In which world are technical features like "how many channels the format supports" or "maximum bit depth" or "progressive decoding" opinions, exactly?
  - jdiff 3y ago
    You can pick and choose which facts to present or misrepresent which/what is important but... that's not going on here. JXL is actually just better by very many metrics. It's only lacking in adoption. There's not something that jpeg-xl.info is ignoring or glossing over. This is just lazy cynicism.
  - iLoveOncall 3y ago
    I was mostly joking, but you can compare a skateboard and a car and make the skateboard look better if you just mention weight and pollution but not top speed, autonomy, etc.
    - vanderZwan 3y ago
      Well, ok, that's a fair point: from this table alone you can't say anything about computational complexity or implementation difficulty. And I cannot honestly say anything about that. I agree that it's a valid question to ask. I'm afraid that your first reply misfired a bit if that was what you wanted to get across though.

JyrkiAlakuijala 3y ago

AVIF has progressive support in the spec, but it has not yet been implemented in an encoder and it is very likely going to be less dense than the non-progressive coding. My guesswork is that it will be ~10 % less dense than non-progressive once implemented, but it is just a guess with my pass experiences of other codec experiments trying to do such things. Otherwise both formats have all features. JPEG XL is yuv444 by default whereas AVIF tends to favor yuv420 and some encoding/decoding hardware is going to be yuv420 only, so with AVIF one would often need to go software coding to get yuv444 quality.