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I really don’t get it. Why, but why? It’s already confusing as hell, why create yet another standard (variant) with no unique selling point?

pmarreck 1y ago
JPEG XL is not a "variant", it is a completely new algorithm that is also fully backwards-compatible with every single JPEG already out there, of which there are probably billions at this point. It also has pretty much every feature desired in an image standard. It is future-proofed. You can losslessly re-compress a JPEG into a JPEG-XL file and gain space. It is a worthy successor (while also being vastly superior to) JPEG.
- illiac786 1y ago
  I was referring to the new PNG, not to JPEG XL.
  - sdenton4 1y ago
    Looking at TFA, it's placing in the spec a few things that are already widely stacked onto the format (such as animation). This is a very sensible update, and backwards compatible with existing PNG.
    - illiac786 1y ago
      Not sure expanding PNG capabilities is sensible, looking at the overall landscape of image formats.
      - dveditz_ 1y ago
        The capabilities are already expanded in most common implementations. This update is largely blessing those features as officially "standard".
- BobaFloutist 1y ago
  Is there any risk that if I open a JPEG-XL in something that knows what a JPEG is but not what a JPEG-XL is and then save it, it'll get lossy compressed? Backwards compatibility is awesome, but I know that if I save/upload/share/copy a PNG, it shouldn't change without explicit edits, right?
  - illiac786 1y ago
    a sw that does not know what jpeg xl is, will not be able to open jxl files. How would it? Not sure what the previous poster meant with “backward compatible” here. jxl is a different format. It can include every information a jpeg includes, which then maybe qualifies as “backward compatible” but it still is a different format.
    - liuliu 1y ago
      JPEG XL has the mode that in layman's word, allow bit-by-bit round-trip with JPEG. Original JPEG -> JPEG XL -> Recreated JPEG. Sha256(Original JPEG) == Sha256(Recreated JPEG). That's what people meant by "backward compatible".
      - colejohnson66 1y ago
        That’s not “backwards compatible”, but “round tripable” or “lossless reencode”
        illiac786 1y ago
        exactly, it is absolutely not backward compatible. It is lossless-at-bit-level conversion of JPEG, but that doesn’t help older SW in any way.
    - BobaFloutist 1y ago
      Ah, got it. I assumed it was a losselessly compressed JPEG with metadata telling modern software not to compress differently but that older software would open as a normal JPEG, but I guess they meant something else with "backward compatible".
- dylan604 1y ago
  > You can losslessly re-compress a JPEG into a JPEG-XL file and gain space. Is that gained space enough to account for the fact you now have 2 files? Sure, you can delete the original jpg on the local system, but are you going to purge your entire set of backups?
  - illiac786 1y ago
    if you do not want to delete the original jpeg, there is no point in converting them to jpeg xl I would say. Unless serving jxl and saving bandwidth, while increasing your total storage, is worth it to you.
  - account42 1y ago
    Yes the whole point of lossless re-compression is that you do not need to keep the original JPEGs. Of course you don't need to "purge" backups, just let them rotate out normally. Also backup storage is usually cheaper than something that needs to have fast access speeds.
    - dylan604 1y ago
      For people that shoot digital cameras saving as JPEG, it will a very cocky suggestion to tell them to toss out their camera original files! You'll know JPEG-XL if real when camera manufactures allow for XL acquisition instead of legacy JPEG only.
      - spider-mario 1y ago
        > For people that shoot digital cameras saving as JPEG, it will a very cocky suggestion to tell them to toss out their camera original files! But they can recover them from the JXL files, so are they really “tossed out”? It’s not really different than any other form of lossless compression.

pmarreck 1y ago

JPEG XL is not a "variant", it is a completely new algorithm that is also fully backwards-compatible with every single JPEG already out there, of which there are probably billions at this point. It also has pretty much every feature desired in an image standard. It is future-proofed. You can losslessly re-compress a JPEG into a JPEG-XL file and gain space. It is a worthy successor (while also being vastly superior to) JPEG.

illiac786 1y ago
I was referring to the new PNG, not to JPEG XL.
- sdenton4 1y ago
  Looking at TFA, it's placing in the spec a few things that are already widely stacked onto the format (such as animation). This is a very sensible update, and backwards compatible with existing PNG.
  - illiac786 1y ago
    Not sure expanding PNG capabilities is sensible, looking at the overall landscape of image formats.
    - dveditz_ 1y ago
      The capabilities are already expanded in most common implementations. This update is largely blessing those features as officially "standard".
BobaFloutist 1y ago
Is there any risk that if I open a JPEG-XL in something that knows what a JPEG is but not what a JPEG-XL is and then save it, it'll get lossy compressed? Backwards compatibility is awesome, but I know that if I save/upload/share/copy a PNG, it shouldn't change without explicit edits, right?
- illiac786 1y ago
  a sw that does not know what jpeg xl is, will not be able to open jxl files. How would it? Not sure what the previous poster meant with “backward compatible” here. jxl is a different format. It can include every information a jpeg includes, which then maybe qualifies as “backward compatible” but it still is a different format.
  - liuliu 1y ago
    JPEG XL has the mode that in layman's word, allow bit-by-bit round-trip with JPEG. Original JPEG -> JPEG XL -> Recreated JPEG. Sha256(Original JPEG) == Sha256(Recreated JPEG). That's what people meant by "backward compatible".
    - colejohnson66 1y ago
      That’s not “backwards compatible”, but “round tripable” or “lossless reencode”
      - illiac786 1y ago
        exactly, it is absolutely not backward compatible. It is lossless-at-bit-level conversion of JPEG, but that doesn’t help older SW in any way.
  - BobaFloutist 1y ago
    Ah, got it. I assumed it was a losselessly compressed JPEG with metadata telling modern software not to compress differently but that older software would open as a normal JPEG, but I guess they meant something else with "backward compatible".
dylan604 1y ago
> You can losslessly re-compress a JPEG into a JPEG-XL file and gain space. Is that gained space enough to account for the fact you now have 2 files? Sure, you can delete the original jpg on the local system, but are you going to purge your entire set of backups?
- illiac786 1y ago
  if you do not want to delete the original jpeg, there is no point in converting them to jpeg xl I would say. Unless serving jxl and saving bandwidth, while increasing your total storage, is worth it to you.
- account42 1y ago
  Yes the whole point of lossless re-compression is that you do not need to keep the original JPEGs. Of course you don't need to "purge" backups, just let them rotate out normally. Also backup storage is usually cheaper than something that needs to have fast access speeds.
  - dylan604 1y ago
    For people that shoot digital cameras saving as JPEG, it will a very cocky suggestion to tell them to toss out their camera original files! You'll know JPEG-XL if real when camera manufactures allow for XL acquisition instead of legacy JPEG only.
    - spider-mario 1y ago
      > For people that shoot digital cameras saving as JPEG, it will a very cocky suggestion to tell them to toss out their camera original files! But they can recover them from the JXL files, so are they really “tossed out”? It’s not really different than any other form of lossless compression.