alt Hacker NewsWorth noting that this progressive AVIF, when viewed in Chrome, has only two states: a "base layer" which pops in around 8KB, and the full image which appears 270KB later. The comparison JXL continues to refine during most of the download, so it winds up looking substantially better than the AVIF at around 95KB loaded, and looks pretty good (almost as good as the full 280KB AVIF) by 175KB. I suspect that there are a lot of knobs to turn for both progressive modes, but this particular case could definitely be cherry-picked to favour either codec.
Replies
computerbuster • today at 2:04 AM
I believe wholeheartedly that AVIF's approach is significantly better UX.
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est • today at 1:56 AM
Perhaps it's just a bad example. I suppose avif can support multiple "scans" of progressive encoding as well.
Progressive AVIF is very flexible: it supports up to four passes, at configurable quality and dimension scaling levels. You can have any given pass reference up to two previous ones for refinement (thanks to AV1's strong inter-encoding capabilities), and you add filters to non-final passes (like blurring) to achieve a desired loading aesthetic.
That JXL page happens to use two passes, but the knobs are there to customize the experience to fit the use case.