[wizee]

JPEG-XL provides the best migration path for image conversion from JPEG, with lossless recompression. It also supports arbitrary HDR bit depths (up to 32 bits per channel) unlike AVIF, and generally its HDR support is much better than AVIF. Other operating systems and applications were making strides towards adopting this format, but Google was up till now stubbornly holding the web back in their refusal to support JPEG-XL in favour of AVIF which they were pushing. I’m glad to hear they’re finally reconsidering. Let’s hope this leads to resources being dedicated to help build and maintain a performant and memory safe decoder (in Rust?).

[homebrewer]

It's not just Google, Mozilla has no desire to introduce a barely supported massive C++ decoder for marginal gains either:

https://github.com/mozilla/standards-positions/pull/1064

avif is just better for typical web image quality, it produces better looking images and its artifacts aren't as annoying (smoothing instead of blocking and ringing around sharp edges).

You also get it for basically free because it's just an av1 key frame. Every browser needs an av1 decoder already unless it's willing to forego users who would like to be able to watch Netflix and YouTube.

[lonjil]

I don't understand what you're trying to say. Mozilla said over a year ago that they would support JXL as soon as there's a fast memory safe decoder that will be supported.

Google on the other hand never expressed any desire to support JXL at all, regardless of the implementation. Only just now after the PDF Association announced that PDF would be using JXL, did they decide to support JXL on the web.

> avif is just better for typical web image quality, it produces better looking images and its artifacts aren't as annoying (smoothing instead of blocking and ringing around sharp edges).

AVIF is certainly better for the level of quality that Google wants you to use, but in reality, images on the web are much higher quality than that.

And JXL is pretty good if you want smoothing, in fact libjxl's defaults have gotten so overly smooth recently that it's considered a problem which they're in the process of fixing.

[bawolff]

> I don't understand what you're trying to say. Mozilla said over a year ago that they would support JXL as soon as there's a fast memory safe decoder that will be supported.

Did they actually say that? All the statements i've seen them have been much more guarded and vauge. More of a, maybe we will think about it if that happens.

[lonjil]

> If they successfully contribute an implementation that satisfies these properties and meets our normal production requirements, we would ship it.

That's what they said a year ago. And a couple of Mozilla devs have been in regular contact with the JXL devs ever since then, helping with the integration. The patches to use jxl-rs with Firefox already exist, and will be merged as soon as a couple of prerequisite issues in Gecko are fixed.

[magicalist]

Their standards position is still neutral; what switched a year ago was that they said they would be open to shipping an implementation that met their requirements. The tracking bug hasn't been updated[2] The patches you mention are still part of the intent to prototype (behind a flag), similar to the earlier implementation that was removed in Chrome.

They're looking at the same signals as Chrome of a format that's actually getting use, has a memory safe implementation, and that will stick around for decades to justify adding it to the web platform, all of which seem more and more positive since 2022.

[1] https://mozilla.github.io/standards-positions/#jpegxl

[2] https://bugzilla.mozilla.org/show_bug.cgi?id=1539075

[wizee]

I disagree about the image quality at typical sizes - I find JPEG-XL is generally similar or better than AVIF at any reasonable compression ratios for web images. See this for example: https://tonisagrista.com/blog/2023/jpegxl-vs-avif/

AVIF only comes out as superior at extreme compression ratios at much lower bit rates than are typically used for web images, and the images generally look like smothered messes at those extreme ratios.

[kps]

Not everything in the world is passive end-of-the-line presentation. JPEG-XL is the only one that tries to be a general-purpose image format.

[asadotzler]

If that's the case, let it be a feature of image editing packages that can output formats that are for the web. It's a web standard we're talking about here, not a general-purpose image format, so asking browsers to carry that big code load seems unreasonable when existing formats do most of what we need and want for the web.

[crote]

People generally expect browsers to display general-purpose image formats. It's why they support formats like classical JPEG, instead of just GIF and PNG.

Turns out people really like being able to just drag-and-drop an image from their camera into a website - being forced to re-encode first it isn't exactly popular.

[robertoandred]

> Turns out people really like being able to just drag-and-drop an image from their camera into a website - being forced to re-encode first it isn't exactly popular.

That’s a function of the website, not the browser.

[jyoung8607]

> That’s a function of the website, not the browser.

That's hand-waving away quite a lot. The task changes from serving a copy of a file on disk, as every other image format in common use, to needing a transcoding pipeline more akin to sites like YouTube. Technically possible, but lots of extra complexity in return for what gain?

[bananalychee]

Even though AVIF decoding support is fairly widespread by now, it is still not ubiquitous like JPEG/PNG/GIF. So typically services will store or generate the same image in multiple formats including AVIF for bandwidth optimization and JPEG for universal client support. Browser headers help to determine compatibility, but it's still fairly complicated to implement, and users also end up having to deal with different platforms supporting different formats when they are served WebP or AVIF and want to reupload an image somewhere else that does not like those formats. As far as I can tell, JXL solves that issue for most websites since it is backwards-compatible and can be decoded into JPEG when a client does not support JXL. I would happily give up a few percent in compression efficiency to get back to a single all-purpose lossy image format.

[hirako2000]

Even Google photo does not support avif.

It's almost as if Google had an interest in increased storage and bandwidth. Of course they don't but as paying Driver used I'm overcharged for the same thing.

[magicalist]

> Even Google photo does not support avif

I have no previous first-hand knowledge of this, but I vaguely remember discussions of avif in google photos from reddit a while back so FWIW I just tried uploading some avif photos and it handled them just fine.

Listed as avif in file info, downloads as the original file, though inspecting the network in the web frontend, it serves versions of it as jpg and webp, so there's obviously still transcoding going on.

I'm not sure when they added support, the consumer documentation seem to be more landing site than docs unless I'm completely missing the right page, but the API docs list avif support[1], and according to the way back machine, "AVIF" was added to that page some time between August and November 2023.

[1] https://developers.google.com/photos/library/guides/upload-m...

[hirako2000]

You are correct it is possible to upload avif files into Google Photo. But you lose the view and of course the thumbnail. Defeating the whole purpose of putting them into Photo.

Given it's an app, they didn't even need Google chrome to add support. Avif is supported on Android natively.

[magicalist]

> You are correct it is possible to upload avif files into Google Photo. But you lose the view and of course the thumbnail.

I'm not sure what you mean. They appear to act like any other photo in the interface. You can view them and they're visible in the thumbnail view, but maybe I'm misinterpreting what you mean?

[lonjil]

Some years ago, the Google Photos team asked the Chrome team to support JXL, so that they could use it for Photos. The request was ignored, of course.

[hirako2000]

They could have added support themselves to the app as it doesn't use the WebView

[ascorbic]

Google Photos isn't just the app

[danielheath]

The killer feature of JXL is that most websites already have a whole bunch of images in JPEG format, and converting those to JXL shrinks them by about 30% without introducing any new artifacts.

[magicalhippo]

> Mozilla has no desire to introduce a barely supported massive C++ decoder for marginal gains

On a slightly related note, I wanted to have a HDR background image in Windows 11. Should be a breeze in 2025 right?

Well, Windows 11 only supports JPEG XR[1] for HDR background images. And my commonly used tools did either not support JPEG XR (Gimp fex) or they did not work correctly (ImageMagick).

So I had a look at the JPEG XR reference implementation, which was hosted on Codeplex but has been mirrored on GitHub[2]. And boy, I sure hope that isn't the code that lives in Windows 11...

Ok most of the gunk is in the encoder/decoder wrapper code, but still, for something that's supposedly still in active use by Microsoft... Though not even hosting their own copy of the reference implementation is telling enough I suppose.

[1]: https://en.wikipedia.org/wiki/JPEG_XR

[2]: https://github.com/4creators/jxrlib

[infinet]

Another JPEG XR user is Zeiss. It saves both grayscale and color microscope images with JPEG XR compression in a container format. Zeiss also released a C++ library (libczi) using the reference JPEG XR implementation to read/write these images. Somehow Zeiss is moving away from JPEG XR - its newer version of microscope control software saves with zstd compression by default.

[greenavocado]

"Marginal Gains"

Generation Loss – JPEG, WebP, JPEG XL, AVIF : https://www.youtube.com/watch?v=w7UDJUCMTng

[edflsafoiewq]

Marginal gains over AVIF.

(Also I am highly skeptical of the importance of these generation loss tests.)

[jlouis]

Very nice in video workflows, where it's common to write out image sequences to disk.

[greenavocado]

Social media exists

[xeeeeeeeeeeenu]

>avif is just better for typical web image quality,

What does "typical web image quality" even mean? I see lots of benchmarks with very low BPPs, like 0.5 or even lower, and that's where video-based image codecs shine.

However, I just visited CNN.com and these are the BPPs of the first 10 images my browser loaded: 1.40, 2.29, 1.88, 18.03 (PNG "CNN headlines" logo), 1.19, 2.01, 2.21, 2.32, 1.14, 2.45.

I believe people are underestimating the BPP values that are actually used on the web. I'm not saying that low-BPP images don't exist, but clearly it isn't hard to find examples of higher-quality images in the wild.

[jnd-cz]

Can AVIF display 10 bit HDR with larger color gamut that any modern phone nowadays is capable of capturing?

[CharlesW]

> Can AVIF display 10 bit HDR with larger color gamut that any modern phone nowadays is capable of capturing?

Sure, 12-bit too, with HDR transfer functions (PQ and HLG), wide-gamut primaries (BT.2020, P3, etc.), and high-dynamic-range metadata (ITU/CTA mastering metadata, content light level metadata).

JPEG XL matches or exceeds these capabilities on paper, but not in practice. The reality is that the world is going to support the JPEG XL capabilities that Apple supports, and probably not much more.

[arccy]

if you actually read your parent comment: "typical web image quality"

[ansgri]

Typical web image quality is like it is partly because of lack of support. It’s literally more difficult to show a static HDR photo than a whole video!

[zozbot234]

PNG supports HDR with up to 16 bits per channel, see https://www.w3.org/TR/png-3/ and the cICP, mDCV and cLLI chunks.

[lonjil]

With incredibly bad compression ratios.

[mort96]

HDR should not be "typical web" anything. It's insane that websites are allowed to override my system brightness setting through HDR media. There's so much stuff out there that literally hurts my eyes if I've set my brightness such that pure white (SDR FFFFFF) is a comfortable light level.

I want JXL in web browsers, but without HDR support.

[magicalhippo]

There's nothing stopping browsers from tone mapping[1] those HDR images using your tone mapping preference.

[1]: https://en.wikipedia.org/wiki/Tone_mapping

[twotwotwo]

Wanted to note https://issues.chromium.org/issues/40141863 on making the lossless JPEG recompression a Content-Encoding, which provides a way that, say, a CDN could deploy it in a way that's fully transparent to end users (if the user clicks Save it would save a .jpg).

(And: this is great! I think JPEG XL has chance of being adopted with the recompression "bridge" and fast decoding options, and things like progressive decoding for its VarDCT mode are practical advantages too.)

[kps]

> (in Rust?)

Looks like that's the idea: https://issues.chromium.org/issues/462919304

[kllrnohj]

> 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.

[lonjil]

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]

> 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.

[spaceducks]

> 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".

color banding is not a result of lossy compression*, it results from not having enough precision in the color channels to represent slow gradients. VarDCT, JPEG XL's lossy mode, encodes values as 32-bit floats. in fact, image bit depth in VarDCT is just a single value that tells the decoder what bit depth it should output to, not what bit depth the image is encoded as internally. optionally, the decoder can even blue-noise dither it for you if your image wants to be displayed in a higher bit depth than your display or software supports

this is more than enough precision to prevent any color banding (assuming of course the source data that was encoded into a JXL didn't have any banding either). if you still want more precision for whatever reason, the spec just defines that the values in XYB color channels are a real number between 0 and 1, and the header supports signaling an internal depth up to 64 bit per channel

* technically color banding could result from "lossy compression" if high bit depth values are quantized to lower bit depth values, however with sophisticated compression, higher bit depths often compress better because transitions are less harsh and as such need fewer high-frequency coefficients to be represented. even in lossless images, slow gradients can be compressed better if they're high bit depth, because frequent consistent changes in pixel values can be predicted better than sudden occasional changes (like suddenly transitioning from one color band to another)

[12_throw_away]

> performant and memory safe decoder (in Rust?).

Isn't this exactly the case that wuffs [1] is built for? I had the vague (and, looking into it now, probably incorrect) impression that Google was going to start building all their decoders with that.

[1] https://github.com/google/wuffs

[lonjil]

WUFFS only works for very simple codecs. Basically useless for anything complex enough that memory bugs would be common.