Google Upgrades WebP To Challenge PNG Image Format

New submitter more writes with news that Google has added to its WebP image format the ability to losslessly compress images, and to do so with a substantial reduction in file size compared to the PNG format. Quoting: "Our main focus for lossless mode has been in compression density and simplicity in decoding. On average, we get a 45% reduction in size when starting with PNGs found on the web, and a 28% reduction in size compared to PNGs that are re-compressed with pngcrush and pngout. Smaller images on the page mean faster page loads."

Comments

NIH

[Anonymous Coward]

Why not update the png format? See subject.

Re:NIH

[retech]

Because that requires a committee and would take 10x as long, if ever, to get done.

Re:NIH

[BitZtream]

You don't have to pay for a JPEG license, try again.

Re:NIH

[Anonymous Coward]

TIFF exists. The world doesn't need another file format where most clients don't implement the full standard and the user can never expect a file in that format to be reliably readable everywhere.

Re:NIH

[Anonymous Coward]

If it truly is a significant innovation, it should sail through the standards approval process

Hahahahahahahahahahahahahahahahaaaaaaa

Wow, you've never actually dealt with a standards body before, have you?

Re:NIH

[Anonymous Coward]

But extensions are good for adding information, not removing it. You could probably implement whatever compression enhancements Google made to WebP in PNG through extensions, but probably not in a way that makes old versions of libpng still produce usable results while still having a reduced filesize. At which point it doesn't really matter if you add it to WebP or PNG, the backward compatibility benefit of PNG extensions can't be exploited either way

Re:NIH

[Kjella]

If it truly is a significant innovation, it should sail through the standards approval process as a recognized extension.

Which is not actually that helpful, because then you have tons of PNG-capable applications that can't read PNGs. TIFF used to be this way, where TIFF actually means it can be compressed like ten different ways and support was very mixed. If you have a significant new non-backwards compatible format, just releasing it as a new format is maybe just as easy.

Re:NIH

[timeOday]

Why not update the png format?

Recycling a name for a new incompatible format is a terrible idea. If I have a png image and software that supports pngs, I should be able to read that image, period.

Re:NIH

[petermgreen]

One of the key design features of PNG was that any PNG should be able to be read by any decoder. That is why PNG has relatively few options on how the core data is encoded*

Adding optional stuff is ok (unless it's animation......) but if you want to make a key change to the core of the format I suspect the PNG guys would tell you to go make your own format based on PNG but with it's own specification, file extension and "magic number" (as was done for MNG, and JNG).

* a handful of filter types all of which are easy to implement, one compression algorith, one byte order standard, 15 allowed color/bitdepth combintions (the majority of which represent very comon combinations and all of which can be easilly mapped to 24-bit RGB).

Re:NIH

[Guspaz]

JPEG XR produces images similar to JPEG-2000 while having complexity similar to JPEG, supports transparencies, requires support for lossless compression (unlike JPEG) since lossless is just a quantizer setting, and it's already supported by IE9.

That last bit is probably the most important part. IE's marketshare is shrinking, but it's still big enough that any format it doesn't support is unlikely to see widespread support as the only format available for a site. I doubt IE will ever support WebP, and as such, no website will ever really be able to use WebP. Not unless they do browser detection, and most sites won't bother with multiple image compression formats, they're going to pick the best common one they can, which is currently PNG or JPEG.

Remember PNG alpha support... Until IE supported it, nobody really used it. Once IE did, it became mainstream.

Re:NIH

[ThePhilips]

Here you go, boy.

Right now JPEG org promises that you will not be sued for implementing the basic JPEG 2000.

Re:NIH

[0123456]

Which is not actually that helpful, because then you have tons of PNG-capable applications that can't read PNGs. TIFF used to be this way, where TIFF actually means it can be compressed like ten different ways and support was very mixed.

Only ten different ways? Back in the early 90s I was creating TIFF files that I doubt anyone can display these days; we had our own TIFF tags assigned and could compress files however we wanted to.

This is why TIFF was:

1. Very useful for app developers.
2. A total disaster for interoperability.

Re:NIH

[PhilHibbs]

The images you get from Image Search are Google's version of the image which have been resized to fit the search layout. I would still be surprised if that made Google the number 1, I would have thought Akamai would be the top slot, or Facebook.

Re:NIH

[Ichijo]

Recycling a name for a new incompatible format is a terrible idea. If I have a png image and software that supports pngs, I should be able to read that image, period.

An that goes double for .avi files!

Re:NIH

[Kickasso]

It's OK, nobody uses JPEG 2000 anyway.

Re:NIH

[Anonymous Coward]

Why would he? The standards body that approved it didn't.

Re:NIH

[pclminion]

TIFF used to be this way, where TIFF actually means it can be compressed like ten different ways and support was very mixed.

TIFFs still are this way, it just seems like everything is "all better" because people throw up their hands and use libtiff, which actually handles a large fraction of the weird shit that's out there. If there were not a peculiar group of masochists who decided this was something worth tackling things would seem quite different. If you wanted to sit down and write a TIFF library yourself that was actually capable of loading a majority of TIFF files out there, you'd spend years doing it.

If you don't believe me, look inside libtiff. "Initialize Thunderscan! To the turrets!"

Awesome

[Anonymous Coward]

Another unsupported format from Google.

It's interesting how successful they are at dominating/directing so many areas of the Internet, but they seem so ineffectual in other areas like this and the video format they are trying to get the world to switch to.

Re:Awesome

[Xanny]

They are converting all of youtube to WebM, and it is the only royalty free web video codec. I'm pretty sure they will beat h.264 in the long run because free wins in the end. The fact the encoding is behind the scenes doesn't matter. In a decade html5 video will be defined by webm because no one wants to license h.264 for encoding products.

Re:Awesome

[PwnzerDragoon]

and it is the only royalty free web video codec.

Except Theora. Though from what I've seen WebM has the edge in video quality.

Re:Transparency yet?

[The MAZZTer]

Yes, it's in TFA url and title. :)

Is google's image format ICC capable?

[Jackie_Chan_Fan]

... because Chrome is STILL NOT color managed.

Re:Is google's image format ICC capable?

[DarkXale]

>"Last month we announced WebP support for animation, ICC profile, XMP metadata and tiling."
I assume thats a 'yes'.

Re:Is google's image format ICC capable?

[Farmer Tim]

I assume this would be useful for correcting for differences in displays?

Not just displays, cameras, scanners and printers also use ICC profiles to compensate for the fact that they all capture and reproduce colours slightly differently. This is a good place to read some basics.

If the emphasis is on compression...

[Tastecicles]

...doesn't anyone think it might be time to revisit fractal image compression and maybe look at ways of improving iterated function systems and their associated algorithms (I might give Mike Barnsley a call and ask him how his IFS patents are developing if you're nice and mod me up)?

Re:This is a big deal!

[Trixter]

I didn't realize it was even possible to make such a big improvement in lossless image compression.

You falsely assume that PNG was state-of-the-art in lossless compression. PNG took a great idea (filter the image and take advantage of the 2-D correlation present in most real-world images) and coupled with it a terrible idea (zlib for the back-end compression of the filter output). You're supposed to do order-0 compression (ie. statistical, like Huffman coding) on the filter residuals, not pattern-match searching (zlib). zlib is a great piece of software, but like all tools, there are things it is very well-suited for and others it is not well-suited for. This was a misstep by the PNG team.

The choice the PNG people made was fueled by the Unisys GIF/LZW patent of the time, and at that time IBM also had a patent on range coders. So I guess it's understandable why they didn't use those order-0 methods on the filter residuals. But it was a huge mistake to knee-jerk away from ALL statistical methods and choose zlib as the back-end. They could have used basic Huffman; not sure why they didn't.

An even better way to decrease page load time:

[larry bagina]

block google analytics.

It's been a long time coming

[Twinbee]

As someone who would love to use variable transparency (translucency) pictures on my own website, this story is very cool news. For one thing, it allows pictures to have drop shadows on varied backgrounds, without having to be forced to save as full 32bit PNG.

I'm now somewhat disappointed PNG didn't get this far sooner. It's served its purpose well over time, but I didn't realize there was still so much room for compression.

Congrats to Google, and I hope the other browser quickly adopt this apparently great picture format. I wonder how its animation side compares to APNG or MNG. The PC has always been gasping for decent lossless animation support, even though the Amiga 20 years ago had seemingly a dozen animation formats to choose from. Also, web browsers have (or at least had) great difficulty in playing animations at higher than around 16-25fps (apart from flash). It's a pretty sad state of affairs all round really.

Re:It's been a long time coming

[porneL]

You don't have to save full 32-bit PNG. 8-bit PNG supports full alpha as well -- in all applications except Photoshop.

See http://pngmini.com/ or https://github.com/pornel/improved-pngquant

Re:It's been a long time coming

[porneL]

The original pngquant was quite bad indeed (it did support alpha, but poorly). It had lots quality trade-offs for MS-DOS era machines.

The modern rewrite is much better in terms of quality and it's especially tuned for good alpha channel support.

are image standards too established?

[rlwhite]

As someone who rooted for the adoption of JPEG2000, I wonder, have we reached the point where the existing major image formats are 'good enough' and so established that new standards are unlikely to unseat them?

Re:are image standards too established?

[Sloppy]

It doesn't have to unseat anything. Google is in the interesting position of having some websites with a significant amount of traffic and a web browser with a significant number of users. All they have to do is have Chrome send it in the Accept header and have their sites pay attention to that header. Instant n% reduction of bandwidth used by images.

Right there, technological progress can stop and Google still comes out ahead. (Ignoring what they've paid to people to come up with WebP.) No rival has to be unseated.

OTOH, once your site starts receiving a significant number of image/webp (or whatever they're using) in the Accept headers from Chrome (and Opera!) users, you have incentive to reconsider taking advantage, and the network effect has started, bouncing back'n'forth between site developers and browser developers.

JPEG2000 didn't go this way because of the patent issue; from the very get-go, everyone knew they weren't allowed to use it. With WebP, it's either a mystery (if you're cautious) or allowed (because you trust that Google did a good patent search). Unlike JPEG2000, nobody has stepped forth and shown for sure that the tech needs to be sequestered for a couple decades. The default assumption about its legality is different.

Re:This is a big deal!

[Edgewize]

That seems like an oversimplification since the DEFLATE algorithm includes a huffman encoding step, and it is within the specs for the compressor to simply never emit back-references. It would be a horrible bug in the implementation of zlib to have worse compression performance than a basic huffman encoding.

Re:is his really necessary for tomorrows internet?

[Hatta]

CSS3 will soon eliminate the need for rounded corner images and gradient backgrounds

There never was any need for rounded corners and gradient backgrounds.

PNG8 is here

[porneL]

I'm working on it -- or rather squeezing every last drop of the existing format.

http://pngmini.com/vs-webp/

With good PNG8+alpha quantization you can get compression in the same league as WebP (although WebP is still better) and basically 100% browser support (it degrades well in IE6).

Re:This is a big deal!

[Trixter]

That seems like an oversimplification since the DEFLATE algorithm includes a huffman encoding step, and it is within the specs for the compressor to simply never emit back-references. It would be a horrible bug in the implementation of zlib to have worse compression performance than a basic huffman encoding.

(DEFLATE doesn't use Huffman, it uses Shannon-Fano as it's entropy encoding step.) While zlib can be configured to not emit back-references and just entropy-encode the input, PNG does not use this mode. I suspect it was because they were trying to stay as far away from the Unisys patent as possible (meaning, "image -> entropy" (GIF) and "image -> filter -> entropy" (PNG) might have seemed too similar/infringing).

zlib can not only compress worse than just entropy; if unchecked, it could actually output "compressed" data that is larger than the original. This happens when you give it uncompressable data and it tries to match patterns anyway. Of course it has a check for this; if the output is larger than the input, it just stores the input uncompressed. 7-ZIP LZMA doesn't have this, so that's why 7-ZIP's output can sometimes be larger than the input. (They fixed that in LZMA2.)

4% Compression?

[Anonymous Coward]

Using 37 topographic map png images ranging from 307K to 1.6M, the best compression I got was 4.09%

Typical compression was roughly 1.7%

In no way was I able to get 24% or anything close to that. But maybe I'm doing it wrong...

There is more to the world than the web.

[westlake]

They are converting all of youtube to WebM, and it is the only royalty free web video codec. I'm pretty sure they will beat h.264 in the long run because free wins in the end.

The key word here is "converting."

H.264 is a core technology in digital video with 1,081 licensees. AVC/H.264 Licensees

Studio production.

Broadcast, cable and satellite distribution. Industrial applications. Home video.

You can play Google's YouTube transcode in your browser. WebM may find an anchorage in video chat.

But that is pretty much all you can do with WebM right now.

There is no such thing as amatuer or studio grade production hardware. No such thing as a WebM security camera.

TFA! Read it!

[Zephiris]

Then linked from the original article is the study is basing it on. http://code.google.com/speed/webp/docs/webp_lossless_alpha_study.html
It's essentially saying that nearly the entire reason it's a fraction smaller in lossless mode is because there's no alpha support. Combining it the "optional" alpha mode with the "optional" lossless mode merely makes it near-identical in size to PNG, according to them.

The more features you take out, and the more you degrade the pictures, the smaller they are in comparison to the original. Is this somehow surprising?