Slashdot Mirror
JPEG Patent Challenged
ChocLinux writes "The Public Patent Foundation has filed a request at the US Patent Office to revoke Compression Labs' data compression patent, which it is reportedly using to harrass anyone that implements the JPEG format. 'CLI's aggressive assertion of the '672 patent is causing substantial public harm by threatening this international standard on which the public relies,' says Pubpat in its filing."
This is covered in details over at Groklaw
Help fight continental drift.
If, and I say IF the patent is valid from a 'no prior art' and is not intuitively obvious
That's one heck of an "if". It appears that PUBPAT has found prior art in a now-expired patent.
If the patent is valid and the public has used it regardless, then they are within their rights (legal and quite likely moral) to defend it.
Unless an alleged infringer can successfully make a laches defense.
I assume that they filed under the current system since, if the old system of 17 years after the granting of the patent were in place at the time of filing, the patent would have already expired over a year ago.
U.S. patents are issued with a term of grant + 3.5 years. Three renewals are available: grant + 7.5 years, grant + 11.5 years, and the full term. For this and other U.S. patents subsisting as of mid-1996, when the Uruguay Round Agreements Act came into effect in the United States, the full term is the longer of filing + 20 years or grant + 17 years.
Conversion from truecolor to indexed PNG is lossy.
And so is conversion from truecolor to 256-color BMP, and so, in fact, is cropping a BMP to include the middle 27.6% of the image. Is BMP lossy?
Of course not. You can do things to any file to lose information, and reducing the number of colors in an image is obviously one of them. You can't say text files are lossy just because you can convert a Unicode text file to ASCII and lose some characters in the process.
Then what Free format was designed to replace JPEG?
I don't think there are any formats comparable to JPEG currently, and I know that there certainly aren't any in widespread use. That's the whole point of this article. If JPEG users get screwed, then we're in serious trouble. Think about how many photos on the web are in JPEG format, and how many photos on people's computers are JPEG.
Not exactly. In fact JPEG's and GIF's are targetted at two different kinds of images.
Gifs (and later png's) work better for images with large areas of constant color (cartoon type images) where JPEG's are better for photgraphic like images where the the shifts in color are more gradual.
Also JPEG is usually a lossy format (there is a lossless mode, but it's essentially a totally different form of compression) where as GIF and PNG are lossless.
Using the wrong one can result in HUGE filesizes compared to using the right format for the job. Some apear to think a JPEG will always be a smaller final file because lossy should be smaller than lossless, but for drawings and cartoons this is often false. I've seen images (real images from real sources, not some 'ideal' image, or cherry picked image) that are much smaller in png than jpeg unless you turn the quality on the jpeg incoder so low that you can't tell horse from a house.
Mycroft
https://signup.leagueoflegends.com/?ref=4c3ed6600b6ea
If you read the pubpatent filing, their main point is that an earlier patent, issued to the same company, is prior art for all the points in the '672' patent. The earlier patent was filed more than a year (plus one month) prior to the filing of the '672' patent, which makes it legally prior art.
Anyway, the sucker has less than a year to run, as it was filed in October, 1986. Probably why the lampreys at Forgent are pushing so aggressively. It'll only be a cash cow for another 11 months.
Interestingly, I could have been a target of Unisys, except they couldn't have gotten much blood from this stone. I was the original author of the "compress" program, which turned into an early "open source" effort (although the term hadn't been invented at the time). Compress was an implementation of LZW, based on Welch's 1984 paper in Computer. Only later was I informed that it was patented. After it had been incorporated into Berkeley Unix releases and into the GIF format. I was happy when that patent finally expired, but I had absolutely no doubt of its legitimacy.
As for the claimed superiority of PNG over JPEG, I'd say it depends on the application. JPEG was designed precisely and specifically for the purpose of compressing photographic images. Such images
- Do not compress well using techniques like LZW and Huffman coding
- Have intrinsic variation in pixel values due to noise in the recording process
- Don't have precisely straight and sharp edges
These characteristics make them poorly suited to lossless compression techniques, and also mean that a lossy technique will not degrade the image further than the original noisy recording method did. (Unless you turn up the loss level too high.)Because of the "if you have a hammer, every problem looks like a nail" principle, people have used JPEG in applications that it's not suited for -- applications where the lossy compression DOES degrade the image quality, and where a different method (LZW, for example) would in fact give a smaller file. Then other people point at these examples and say "PNG (or GIF) is better than JPEG!" My toolbox has hammers, screwdrivers, wrenches, etc. I try to pick the appropriate tool, and don't hammer with a wrench, for example. The same should be true of our computer tools.
Or more to the point, fourier transforms are good for entropic data in general, but consequently end up distorting non-entropic data such as solid colours. Therefore, the next person to post a screenshot of a program in a JPEG image, especially one from MSPaint, is going to get stabbed repeatedly in the face.
'Yes, firefox is indeed greater than women. Can women block pops up for you? No. Can Firefox show you naked women? Yes.'
Copyrights and patents aren't two names for the same thing. Inventions can be patented; the creative expression of an idea can be copyrighted. The idea itself cannot; see Feist v. Rural .
Laws do not persuade just because they threaten. --Seneca
Think of all the Japanese digital camera manufacturers that sell cameras in the U.S.
They have already been challaged by many, but for the first time someone has a concrete case with 'prior art'. You can read more on this at The Data Compression News Blog
White Knight Charges Forgent http://www.c10n.info/archives/246
[Disclaimer: Shameless self promotion]
PNG is lossless, so it looks good. JPEG is lossy, so it's small. You can get much better compression on photographic (lots of colors, few uniform color areas, few if any geometric features--this is only my crude layman's impression) images using lossy compression with JPEG, and furthermore, it's adjustable so if you need less quality, you can recover more bandwidth. PNG can only compress such images so far, and no farther.
By contrast, PNG can represent alpha transparency, so (if your browser supports it.. hope IE7 is out soon) you can get neat effects with PNG. PNG is also great at presenting images, created with vector graphics, to software that doesn't do vector rendering. That means logos on web pages, line drawings of all sorts such as scientific plots, etc. But the reason it's good for such things is that such images benefit far more from lossless rendering (than photographs or 2d art or the like).
PNG is great technology, but you can't simply put aside JPEG yet. Like PNG, JPEG is good at what it does, what it's intended for.
It's rare that you're presented with a knob whose only two positions are Make History and Flee Your Glorious Destiny.