> and generally its HDR support is much better than AVIF

Not anymore. JPEG had the best HDR support with ISO 21496-1 weirdly enough, but AVIF also just recently got that capability with 1.2 ( https://aomedia.org/blog%20posts/Libavif-Improves-Support-fo... ).

The last discussion in libjxl about this was seemingly taking the stance it wasn't necessary since JXL has "native HDR" which completely fails to understand the problem space entirely.

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lonjil 26 minutes ago | parent [-]

The JXL spec already has gainmaps...

Also, just because there's a spec for using gainmaps with JPEG doesn't mean that it works well. With only 8 bits of precision, it really sucks for HDR, gainmap or no gainmap. You just get too much banding. JXL otoh is completely immune to banding, with or without gainmaps.

	▲	kllrnohj 4 minutes ago \| parent [-]
		> With only 8 bits of precision, it really sucks for HDR, gainmap or no gainmap. You just get too much banding. This is simply not true. In fact, you get less banding than you do with 10-bit bt2020 PQ. > JXL otoh is completely immune to banding Nonsense. It has a lossy mode (which is its primary mode so to speak), so of course it has banding. Only lossless codecs can plausibly be claimed to be "immune to banding". > The JXL spec already has gainmaps... Ah looks like they added that sometime last year but decided to call it "JHGM" and also made almost no mention of this in the issue tracker, and didn't bother updating the previous feature requests asking for this that are still open.