So right away on the first item: >Max image size is limited to 4K (3840x2160) in AVIF, which is a deal breaker to me. You can tile images, but seams are visibl

So right away on the first item: >Max image size is limited to 4K (3840x2160) in AVIF, which is a deal breaker to me. You can tile images, but seams are visible at the edges, which makes this unusable. JPEG XL supports image sizes of up to 1,073,741,823x1,073,741,824. You won’t run out of image space anytime soon. >JXL has a maximum of 32 bits per channel. AVIF supports up to 10. Max resolution and bit depth is certainly massively higher for for JPEG XL, but spec [0] says that: >"NOTE: [AV1] supports 3 bit depths: 8, 10 and 12 bits, and the maximum dimensions of a coded image is 65536x65536, when seq_level_idx is set to 31 (maximum parameters level)." And 12-bits per channel is considered a lot for end user final display formats? It also seems to be supported in browsers too so it's not just theoretical. It looks like back in 2021 there was discussion around this and clarifying that the profiles decided on in 2018/2019 were more about giving targets for hardware acceleration of the time, but software decoders by 2021 supported essentially the whole spec (and it appears to me that another 2 years later now final lingering stuff has been dealt with) [1,2]: >Cyril has proposed a pull request (#130) to better clarify what is and is not supported in AVIF. In short, AVIF supports everything that AV1 supports, which includes 12-bit encoding. The current software decoder implementations also support more or less all of AV1, which can be seen if you try to decode a 12-bit AVIF file in a web browser. And for still images, hardware acceleration isn't important, so as a practical matter unlike AV1 video pure software for max features is fine. So 65k x 65k and 36-bit color appear to be the limit, which definitely isn't as much as JPEG XL, but is pretty respectable for majority of end user usage? Edit to add: the comments there also mention complaints that the JPEG XL author has a history of spreading misinformation about AVIF, "See the article and infographic recently posted by the JPEG-XL author that claims (among other things) that AVIF does not support 12-bit images". So apparently there has been some good old dev drama going on during the last few years which means one may need to be a little suspicious about any "Good summaries" :(. ---- 0: https://aomediacodec.github.io/av1-avif/#profiles-overview https://aomediacodec.github.io/av1-avif/#profiles-overview 1: https://github.com/AOMediaCodec/av1-avif/issues/128 https://github.com/AOMediaCodec/av1-avif/issues/128 2: https://github.com/AOMediaCodec/av1-avif/pull/130 https://github.com/AOMediaCodec/av1-avif/pull/130