Shouldn't those patents be expiring soon?

Edit: Did some more research and the patent risk appears to have passed as of 2016. Still nobody seems to have interest in JPEG2000.

webp was around since 2010 and has google's backing. Microsoft tried their own thing (Jpeg XR; 2009) and the actual JPEG committee announced their work Jpeg XL (with google backing) a while ago, while Apple switched to HEIC/HEIF as of 2017 (HEIC is like webp just based on HEVC aka H.265 instead of vp8 i-frames; and it's a patent mess of course).

There is simply no reason why people in 2016 or now would be interested in a format from 2000 that was a patent minefield until at least 2016.

Except for JPEG the alternatives are also patent minefields...

Are people just more cavalier about the patent risk these days? The problem with JPEG2000 wasn't the patents we knew about, it was the possibility of submarine patents. People were still wary after the GIF debacle. Nobody wanted to be charged $0.05/image after the fact when they've delivered literally billions of images. Plus the courts were seen as very favorable towards patent holders, even when they were acting in bad faith.

It’s too compute intensive

That's kind of scary for something developed in the 90s. It was originally run on Pentiums, K6s, PPC 604s, and the like and it's still too expensive for a Ryzen 7?

Yep. There's a ton of data dependencies, where e.g. you can't begin decoding the next bit until you've finished decoding the current bit. It's all about progressive decoding so there's multiple passes over each group of wavelet coefficients, accessed in a data-dependent sequence. Each wavelet transform involves accessing and interleaving the same 2D arrays in both row- and column-oriented fashions.

These design decisions all made sense when clock rates were exponentiating, but they're all nightmares now that we rely on branch prediction and memory prefetching and superscalar execution units. The codec is simply not a good fit for the computing architectures we have today.

> These design decisions all made sense when clock rates were exponentiating, but they're all nightmares now that we rely on branch prediction and memory prefetching and superscalar execution units. The codec is simply not a good fit for the computing architectures we have today.

Arguably not a good choice for the year 2000, either, considering that all high performance CPUs at that time were out-of-order, superscalar and deeply pipelined.

Images got bigger... it’s not that it’s too expensive it’s just way more expensive that good enough alternatives. There are other reasons too but that’s a surprising one

No.

AFAIK it's pretty standard in DCP files for Digital Cinema.

That was a little of it but the patents expired years ago. The big blockers I saw were basically that it was a very complex format with a specification behind a paywall and no good open-source implementation or test suite. Interoperability was bad until a couple of years ago and it took significant amounts of complex code to make it fast enough to use.

They've subsequently improved that — OpenJPEG is quite good now https://github.com/uclouvain/openjpeg — but probably missed the window for adoption barring a major upset, which is a shame because it's a very powerful codec and has some neat tricks like progressive decoding (imagine if you could have one file in storage and your responsive design simplify specified the HTTP range requests to get for successively large resolution images?). You could ship it in a browser using WASM but I think the browsers are — not without cause — being really reluctant to add new formats and the ensuing security risks without a good reason, and without browser support no format will be more than a niche.