PNG Group Unconcerned About Apple's Patent

melquiades writes: "A recent story raised concerns that Apple's patent on some forms of alpha compositing was blocking the development of PNG, MNG and SVG. Not so, says Greg Roelofs, a member of the PNG group: 'The PNG group did discuss the Apple patent several weeks ago, and we decided it was completely irrelevant to PNG itself, almost certainly irrelevant to the pnmtopng utility and to PNGs animated extension, MNG, and probably irrelevant to SVG as well.' Here's the article on OS Opinion. So if it's not a big deal, why was there a general call for prior art to overturn Apple's patent? It looks like some PNG developers got worried, but the core team thinks there's no problem. Is this just a case of the right hand not knowing that the left hand is paranoid?" Once bitten, twice shy?

Comments

As I understand it...

[Millennium]

It looks to me like the patent covers alpha-masking, not alpha-blending.

As I recall, PNG and SVG both use alpha channels. That is, transparency data is stored as a part of the image's color encoding.

Alpha-masking is different. In this case, an image is defined in the "normal" RGB fashion. Along with it, a second image is stored, which has only alpha information in it, not color. You could say that an alpha channel is inline, whereas an alpha mask is not.

Is the patent ridiculous? Of course it is. But I don't think it would affect PNG and SVG anyway, because they use a different method of storing transparency information.

Apple Unconcerned too?

[Anixamander]

A while back Apple posted this to their web site. It seems they are against RAND licensing fees. I assume that would also include their own technology, but I am really not sure how all this fits together.

is a call to prior art a bad thing?

[Frothy Walrus]

So if it's not a big deal, why was there a general call for prior art to overturn Apple's patent?

is there a problem with this? with the average IQ of a patent lawyer at about 35 these days, you can't be too careful. mark my words, the future of Open Source depends upon it.

Noninfringement Opinion?

[Compulawyer]

I know this is Open Source, but I generally thought that most Open Source software was better engineered than much of the commercial stuff out there. One of the key components in a feasibility study BEFORE other development work begins is legal feasibility . If you don't believe me, dust off your copies of Pressman's Software Engineering and see what HE says. I'm not just making this up.

Part of a legal feasibility study has to be a patent infringement analysis. Whether you agree kthat software should be patentable or not, the fact it that in the US it IS patentable. If someone else made it first and was granted the exclusive right to make that product, then you will infringe on their rights if you make the product.

There is simply no excuse for not doing this analysis. Yes, there is some up-front cost to a patent attorney. However, with a large enough development group, this cost can easily be absorbed by the group at a nominal level per member. The potential consequence is that every developer can find themselves defending a patent infringement suit. The last estimate of which I am aware placed the cost of litigating an "average" infringement suit at just around $500,000.00. If the case is deemed "exceptional," the infringers could potentially have to pay the patentee's legal costs as well as their own, on top of paying damages for the patentee's lost profits.

Bottom line: all this can be avoided by getting a noninfringement opinion by a reputable and competent patent attorney. This is a basic software engineering step and should be performed at the very beginning of the development process. The attorney will even be able to suggest ways you can still go forward with the project, but do so in a way that does not infringe on someone else's rights.

Re:PNG's

[Zed Pobre]

Remove www.debian.org from your list. It does use .png images (and there are half a dozen of them on the main page, at least), just not exclusively.For that matter, including www.gnu.org is somewhat unfair, as they pretty much only use the one image on the entire site, and although it's in jpeg format on the main page, it is also available in .png (in fact, the high resolution version is only available in .png). See http://www.gnu.org/graphics/agnuhead.html.

So who is using PNG? Some of the people you list as not using PNG.

(... mutter mutter ... moderators that don't check claims ... mutter mutter ...)

Re:No one answered melquiades's question

[Doomdark]

No. They didn't patent single-channel alpha blending. They patented 'multi-channel blend'. That is; blending is done by using mask image, not mask (alpha) channel. Each colour component is blended separately; only if mask image uses grayscale (ie. all components have same value) pixels this degenerates to normal alpha-blending.

So, like PNG gurus said, this doesn't relate to PNG; PNG 'only' supports alpha channel (although it's questionable whether full alpha-'image' would be an improvement... but that's what Apple patented).