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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."
Because that requires a committee and would take 10x as long, if ever, to get done.
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
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.
Live today, because you never know what tomorrow brings
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.
block google analytics.
Do you even lift?
These aren't the 'roids you're looking for.
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.
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).
note: i'm known as plugwash most places but i screwd up registering that here somehow in the past and now can't register
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.
It's OK, nobody uses JPEG 2000 anyway.
Why would he? The standards body that approved it didn't.
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.
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