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Comment by tannhaeuser | Hacker News Reader

Is JPEG2000 with progressive/resolution-responsive transcoding still a thing or is HTML <picture> the way to go for responsive images (or maybe WepP)?

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JPEG2000 died a bitter patent death.

Actually, it's alive and well in the form of embedded images in PDFs, where it's known as JPXFilter. Most of the ebooks (scans) I've downloaded from archive.org use it. If it didn't have any huge advantage I doubt they would've chosen it over standard JPEG.

The real problem, as far as I can see, is that JPEG2000 is really slow to decode due to its complexity.

Modern implementations are decent but there's no open source implementation in that class. OpenJPEG is improving but it's much slower than Kakadu (which is what CoreImage uses) or Aware.

shameless plug for my JPEG 2000 codec: https://github.com/GrokImageCompression/grok . Performance currently around 1/3 Kakadu

Heh, yes - I've been following that since you announced it. It'd be really nice if we could start getting the OSS toolchain onto a JP2 implementation with decent performance — I think jasper really soured the reputation for many people.

The PDF reader is pretty interesting, because don't modern browsers ship with PDF readers? To decode the embedded JPEG2000s, the browser has to be able to decode them right?

PDFs are packaged Postscript. Postscript is a Turing complete language and the output of a script is a page.

PDFs with JPEG2000 images contain a Postscript library to decode these images. That is the code that gets to show them.

Any time you watch a movie at the cinema, JPEG 2000 is in use, decoding the film.

Doesn't Safari support JPEG2000?

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