YHK - yet another hacker news clone

I think one overlooked aspect is that AVIF is container based. Meaning that once sites support, when AV2, AV3 etc. will come out, there won't be a need to go through another very difficult phase of sites adoption - it will still be AVIF just with newer codec inside, and it will be just up to browsers to catch up on newer versions and newer codecs will address technical needs as times goes.

JPEG XL doesn't have that benefit, while sites adoption is arguably a worse issue than browser adoption.

To demonstrate the point even for AVIF itself - it has been in the browsers for a while. Can you use it on common sites? Good luck if you can, even major sites like GitHub and GitLab have issues with it due to some site code depending on hardcoded list of known formats or other similar problems.

Great article!

Overall I am getting that AVIF is better on the web...unless Lossless is needed, in that case better take JPEGXL.

I really hope that some day Firefox supports HDR AVIF images

Ah, Chrome ships JXL when we already have a better codec for the web!

AVIF is a lifesaver for animation with separate transparency layers so the transparency can change position frame by frame. The only other alternative is WebM which has Safari limitations.

> AVIF is basically the keyframe format of AV1 video, with a bunch of still-image-specific optimisations thrown in. Animated AVIF however, is pretty much just a repackaging of AV1 video. You can convert an AV1 MP4 to AVIF and back losslessly - it's just a container change. That's why it performs so much better, because it's built for motion.

So, is animated AVIF only keyframes / p-frames, where each frame is independent from the other? I was under that impression, uncertain if there are any other capabilities it might have (like only updating part of the canvas when only parts change, like GIF supports)

JPEG transcoding is one of the neatest features of JXL; there is so much existing jpeg out there. Eventually that may be unnecessary, but it's looking like this could already save a significant amount of space for photo archive backups for example.

Jake's interest in F1 hasn't waned, which is good to see. I am presuming that picture of an Alpine/Renault at Goodwood is his 18Mb photo, but I could be wrong. Neither has his interest im image compression waned, which is also good to see. But why the move from Google to Firefox?

I am still on webp, thinking that I am on the bleeding edge in a world where artworkers are obsessed with pixels with JPG/PNG as the only formats they know, which is an advance on GIF.

Every browser advertises what formats it will accept and if it is in 'data-saving, low bandwidth mode', so I just configure the CDN to keep the names the same '.jpg' but to send the bestest format for the situation/browser, whether that be webp or AVIF, fetching super-high resolution files from the origin server, outputting them in 'retina' resolution with none of those 'picture' elements referencing half a dozen 'responsive' sizes.

In this way nobody has to care what image format is being served, and if it is deemed that everything is way too compressed, the CDN can be flushed of the cached images, quality increased, and cache rebuilt.

It looks like I will need to update my server configuration to use JPEG XL in the usual five years' time, given the lack of any revolutionary benefit.

I'm only casually following JPEG-XL and my impression from previous reading here on HN was that JPEG-XL was the best solution available for a wide variety of usecases, but it looks like numbers dont match that claim?

Perhaps useful:

* https://caniuse.com/?search=avif

* https://caniuse.com/?search=jpegxl

That F1 image is, in my mind, proof of exactly what is wrong with AVIF. If you look closely the beautiful highlights on the car have been erased and replaced with something plausible. Once you see it you can't unsee it and it boggles my mind that people are still using it as an example.

Granted, AVIF performs impressively for, say, a huge hero image for a blog where you're out to create an overall impression and people aren't going to look at it closely. It does not impress me when I am compressing photos I took with my mirrorless and I expect them to look like photos taken with a mirrorless and not cell phone snaps.

>Animated image formats are dumb and animated JPEG XL is no exception. Video formats are better at video. They're built for it. They're optimised for it. Not just in terms of encoding, but also in terms of playback.

This is something I've felt doesn't get enough attention when comparing JXL and AVIF. AVIF can be the replacement for GIF.

><video muted autoplay> is right there.

>No, I'm not adding a demo. I don't want it on my server. Use video formats for video.

I'm not sure if "Use video formats for video" is saying to use AVIF over JXL or saying to use AV1 over AVIF. If the latter, GIF-like animations have a different enough user expectation that it makes sense to have it as something different from regular videos. Even <video muted autoplay> doesn't encode the full expected behavior because GIFs are not expected to have controls like pause, play and scrub. And even if you hide the controls users will expect similar behavior when opening it in an image viewer or in a new tab. Images do not have controls so they fit better as an image, although maybe they need their own category.

Also, I didn't realize how good AVIF was at progressive rendering. I don't think I knew it could do that at all. I think AVIF is the clear winner for the web, although it is still nice to have JXL for lossless. Somehow I feel that AVIF still hasn't gained as much usage as it should, especially now that it is supported almost everywhere. I think I see more webp than AVIF, and JPEG is still everywhere. Maybe now that JXL is out, developers will take another look? AVIF is supported by 96.35%-98.83% of browsers according to caniuse whereas webp is 97.18%-99.68% and JPEG is 97.28%-99.78%.

I also didn't know there was another Rust JXL decoder separate from jxl-rs named jixel.[0]

[0] https://github.com/awxkee/jixel

1. How long does size, encode time and resize take compared to good old jpeg?

2. Is it possible to encode AVIF with hardware acceleration?

It'd be interesting to scale this up to a lot of images - and have users blind A/B test, like the LLM Arena on Huggingface which helped filter out "benchmaxxing" vs actual intelligence & utility. Because 1) images can be so diverse* and 2) an intrinsic tradeoff might exist between general efficiency and out-of-distribution robustness.

It's hard to rigorously judge a codec from a handful images, especially given the large impact they would have (with a widely adopted codec encoding bazillions of images in the coming years).

* There are many intricate details that go into codecs and visual perception. For instance, our sensitivity to visual errors are dependent on colors (all of hue, saturation, and brightness), spatial frequency of artifacts, local contrast and texture presence, et cetera.

And like OP mentioned, perceptual error metrics (including SSIMULACRA2) aren't perfectly representative of human-evaluated visual quality. For instance, libjxl deliberately makes choices that hurt SSIMU2 scores, but improve human-rated quality.

The question now is how much of AVIF's advantage comes from the encoder compared to the image format itself. If it is the encoder, does JPEG XL even stand a chance of catching up? AVIF will certainly receive further improvements, albeit at a diminishing rate.

I've been using AVIF on my blog for a few years. My blog's image corpus is almost entirely videogame screenshots, and I keep the original PNGs so I can re-encode if better encoders release. Despite playing around with JPEGXL every year or so, AVIF images usually looked better (if only a little) at the same file size (vs JPEGXL).

After reading this article, there's something to point to prove I'm not going crazy.

Most of these images are not at 100%. Use large images and show 100% crops everywhere.

> libjxl's maximum effort is very slow. It produces files 2–7% smaller than its default for photos, and ~25% smaller for the screenshot and illustration, but takes 9–46 seconds, which is 50–180x as long as its default. jixel gets the same results in a couple of seconds.

libjxl's slow speed at efforts >7 is primarily due to an iterative evaluation-optimization loop of a perceptual error metric called Butteraugli (by tuning quantization weights). This, as well as some other computations in libjxl encoding, happen to be data-parallel and run faster on GPUs than multicore CPUs.

In case anyone is interested, I've been working on a GPU-accelerated libjxl port (supporting CUDA and Metal for now) that makes this much faster, closer to libjxl's normal speeds: https://github.com/yunho-c/gjxl - geared for encoding a large batch images into JPEG XL. It's also faster by around 2.9x at normal effort (7).

Unfortunately for the comparison-focused blog post the comparison widgets is pretty bad - you can't quickly compare 2 reference pictures (original vs AVIF or original vs JXL) at different scalings like here https://web.archive.org/web/20200915201019/https://afontenot...

(also like the BPP size metric that is picture size-independent)

Wish that widget with improvements (that allows comparison of 3 pics with 3 buttons: original/codec1/codec2) were the widespread standard (also, "hold" is a rather unergonomic action)

Otherwise, seems like AVIF has had impressive gains in both speed and quality, wonder whether JXL could catch up

AVIF is fantastic format and I use it in my production applications. Spent quite a bit of time looking to the best settings (at least for up to 2k images) and for anyone interested in converting images to AVIF, here's what I've found to work the best for creating the smallest size (10x+ smaller) while still retaining good quality and even supports PNG transparency:

  ffmpeg -i {input_file} -filter_complex "[0:v]format=pix_fmts=yuva444p,split[color][alpha];[alpha]alphaextract[alpha_chan]" -map "[color]" -map "[alpha_chan]" -c:v libaom-av1 -crf 25 -cpu-used 3 -still-picture 1 -aom-params "sharpness=2:enable-chroma-deltaq=1:arnr-strength=0" -color_range pc -colorspace bt709 -color_primaries bt709 -color_trc bt709 {output_file}

To be honest it's starting to sound like Google were right and adding JPEG XL support was a mistake.