#541: jxl Content-Encoding

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Opened Jul 30, 2020

Saluton TAG!

I'm requesting a TAG review of "jxl Content-Encoding".

One of the features of JPEG XL is byte-wise lossless JPEG image repacking. On average, an encoded image is 22% smaller. We propose it as a new HTTP "Content-Encoding".

Further details:

  • I have reviewed the TAG's API Design Principles
  • Relevant time constraints or deadlines: 2020Q3
  • The group where the work on this specification is currently being done: ?
  • The group where standardization of this work is intended to be done: ?
  • Major unresolved issues with or opposition to this specification: none
  • This work is being funded by: ?

We'd prefer the TAG provide feedback as: 🐛 open issues in our GitHub repo for each point of feedback

Discussions

2020-08-24

Minutes

Yves: I made a comment on the issue... It's not ideal to have a content encoding for only one media type but it has been done in the past. Proosed close: satisfied.

Dan: propose close and we can close at the plenary

2021-01-Kronos

Minutes

Peter: My first reaction is - why isn't this just a mime type and Transfer-Encoding?

Rossen: Would that work in all scenarios? For example, going through proxies etc. and coming back with the original encoding?

Peter: It should be able to send a jpg from the server, encode it into jxl along the way, transport it assuming all proxies support it and finally get decoded as jpg back in the browser.

Peter: It seems like very much an edge case for which we're trying to add a lot of overhead for very little benefit.

Lea: It's not clear if and what the savings could be compared to other encodings that are already widely used, gzip etc.

Peter: Computation cost of the encoding/decoding isn't clear. Should they need both copies on the server and rely on content negotiations?

Rossen: Let's leave a comment and move on.

2021-05-Arakeen

Minutes

Reviewd their feedback, propose closing satisfied, still not sure the result is worth the effort but not harmful. To be seen if this is more popular that simply swithing to a jxl image format and mime type.