[joedrew]

(Note: I used to be employed by Mozilla, and in that capacity I was the owner of Mozilla's image decoders. I've been disconnected from all decisions for almost a year, though.)

The main take-home here is that while Google's numbers all show WebP as being objectively better, the metrics they chose for comparison were relatively bad (i.e., some of them didn't take into account colour or didn't model colour correctly), and once you accounted for that the numbers were not nearly as good a story for WebP; in some cases, JPEG outperformed it.

The facts that (1) WebP was not terribly compelling technically, (2) JPEG is already supported by everything on the web, not to mention devices and mobile phones etc, and (3) there's still headroom to improve JPEG in a backwards-compatible way, meant that WebP was (and, it seems, remains) a non-starter.

[dvirsky]

Until JPEG supports transparency, it leaves a vast hole where a good lossy alpha enabled format is needed - namely icons. With the high resolution of mobile devices, using PNG for this use case is a huge waste. Regardless of the quality differences, WebP fills a major pain for mobile and web developers. I really think Mozilla should just support it.

[pornel]

There are a few ways of making fully backwards-compatible "lossy" PNG: http://pngmini.com/lossypng.html

You can have icon files 3-4 times smaller, and large photorealistic images 2 times smaller than the regular PNG.

[panzi]

Yeah, depending on the image putting a bmp into a zip is actually significantly smaller than a png. Well, bmp has no alpha channel, but just as comment to the size of pngs. pngs even uses the zip algorithm in a way that is supposed to be optimized for images, but apparently it is not. E.g. the tiles here are a lot smaller as bmp in a zip: http://panzi.github.io/mandelbrot/

Ok, it put them into one single zip and can't remember if it was solid or not, so it might be the cross-file compression that makes the major difference here.

[pippy]

Plus with chrome already supporting it, WebP has ~50% market share in most countries.

Now we'll have two similar but competing technologies and web developers will simply resort to the older formats.

[milsorgen]

How much of a gain do you get in WebP versus a properly optimized PNG for icons? I can't imagine it's a compelling difference.

[dbcooper]

I had read in the past that HEVC was probably the best for still image lossy compression. [1]

Does anyone have further information on this?

[1] http://en.m.wikipedia.org/wiki/High_Efficiency_Video_Coding#...

[derf_]

Best from a compression perspective, perhaps. There's the minor detail of it being patent-encumbered. There's no license pool available yet, so you couldn't pay for it if you wanted to. The proposed terms of the pool that is organizing (with some of the known patent holders refusing to join) would require up to $25mln/year for the video codec. No idea if you'd be able to get a better deal for still-images only.

Meanwhile, JPEG is free.

[sp332]

According to the study linked in OP, it's still true. https://people.mozilla.org/~josh/lossy_compressed_image_stud...

[cromwellian]

But is there headroom for JPEG to replace animated gifs? If I look at mobile social apps these days, animated GIFs eat up enormous amounts of data. JPEG doesn't seem to have an answer for this, and no one has yet, it appears, made the <video> element work for this use case.

[mbell]

> no one has yet, it appears, made the <video> element work for this use case.

Gfycat seems to be getting more and more popular or at least I'm personally starting to see a lot more of their links in place of imgur gif links.

http://www.gfycat.com/

[mmastrac]

Expanding on Ray's comment above, this is really the compelling use case for WebP: a better container that does it all. Right now we have PNG, GIF and JPEG for three different use cases: animation, transparency and lossy encoding.

I can't easily pick and choose which of these I want, which means that we end up with 20MB GIFs that could easily be 1/5 the size, and crazy hacks to get lossy images working with transparency.

This is particularly painful for HTML5 gaming in my previous experience. For one of my projects that involved a giant, high-res game board with transparency (Nick's online Pai Sho), I ended up manually slicing the board up, converting center pieces to JPEG and leaving the edges in PNG. The images are all pasted together to make the final, seamless experience. What a PITA!

[jlebar]

> no one has yet, it appears, made the <video> element work for this use case.

4chan has, and it's significant not only because they have a lot of traffic, but also because their implementation has to be pretty solid -- 4chan users would love nothing more than to troll the administrators by breaking this.

http://blog.4chan.org/post/81896300203/webm-support-on-4chan

[infogulch]

Yes, no one except for Twitter: http://mashable.com/2014/06/20/twitter-gifs-mp4/

[joedrew]

Honestly, animated GIF (like all other image formats) is a terrible format for video-style stuff. It's fine for line art (well, sort of fine, anyways), but if you actually using it for video you really should be using <video>, because it takes into account temporal information. (gfycat is a service based around this already.)

It might be possible to do an APNG-style backwards-compatible animated JPEG, but it'll still be worse at it than video formats will be.

[TheZenPsycho]

Thanks to the ACID3 test, all modern browsers support animation in SVG and svg in an img tag. Which means you can do extremely small vector based animations, or write an encoder that embeds jpegs and animates them like a film strip. You can have alpha transparency using a mask image via SVG filters. You can get really fancy and animate with deltas. The efficiency you lose by the base64 encoding is regained by gzipping.

[ama729]

APNG (https://en.wikipedia.org/wiki/Apng) is the answer, but Chrome doesn't support natively.

[fournm]

Webm's definitely been getting some traction as a replacement, if 4chan's support is anything to go by.

[InclinedPlane]

Twitter now routinely auto-converts animated gifs into embeded web video.

[rasz_pl]

you can use javascript mpeg1 decoder instead of <VIDEO> you get auto playing animated mpeg files instead of gif mpeg is pretty much jpeg stream with bonus I frames

https://github.com/phoboslab/jsmpeg

example:

http://phoboslab.org/log/2013/05/mpeg1-video-decoder-in-java...

[coldtea]

>If I look at mobile social apps these days, animated GIFs eat up enormous amounts of data.

In mobile apps? Are they really animated GIFs?

[est]

mjpeg? It's used in many DC/DV.

We need a copy-pastable, mute by default <video> format to replace GIFs.

[leccine]

Could you conduct a detailed article and publish it please? I think it would be useful for people who are interested in this but don't have the background about JPEG or WEBP internals.

NVM I found what I was looking for:

http://people.mozilla.org/~josh/lossy_compressed_image_study...