PNG (image format) 1.1 spec released 30
Greg Roelofs writes "Graphics developers (yo, GIMP folks!) will be mildly amused to know that the PNG Development Group has released version 1.1 of the Portable Network Graphics specification. It includes a significantly rewritten section on gamma correction, a couple of new chunks for color correction, and some little stuff relating to suggested palettes, alpha-channel processing, etc. A complete pseudo-context-diff is available. Note also that ISO/IEC standardization is underway, and the PNG home page has even been spiffed up a tiny bit. Whoa. "
good idea, heywire over spec... (Score:1)
hopefully this one will help to fix that (or at least have a different name for the compiled lib when they release that)
Can't replace GIF until ... (Score:1)
- It has a good standard way to do animation--that's the vaporware known as MNG, right?
- It is fully and correctly supported by the Big Two browsers; this would include full alpha blending, for backgrounds as well as inlines. It would be A Good Thing to ensure that Mozilla does this.
I've also noted that PNG can be quite a lot larger than GIF for certain things, like those awful transparent spacer images, and certain small things like flat two-color text images such as those used occasionally as buttons or labels. Not the most important shortcoming, but a few of those can add up quickly.Until then, PNG will remain a turbo-studly curiosity, used mostly in niche applications.
I still love it, however, and want it to succeed.
Why use PNG? (Score:1)
To me, it seems that TIFF is a mature format with all the options and extensibility that anyone could want. About the only thing I can think of off the top of my head that's missing is a standard tag for LZ77 compression like that used in PNG. With enough lobbying and/or agreement among developers, that could be fixed too.
(Note: I realize PNG's advantages over GIF, and over some other image formats. It's TIFF I'm particularly interested in.)
Where's "MNG"? (Score:1)
format for what, two years? The PNG folks said
animation and other multi-image technologies don't
belong in PNG (not that I can see the reason) and
they've been promising this MNG thing. Isn't it
time to start doing some actual work on this stuff?
Animation is close to essential in webwork today.
Where's "MNG"? (Score:1)
How did this get a score of 1? It should be -1. (Score:1)
Why use PNG? (Score:1)
Kinda like the old GIF interlacing, except turbo-studly.
Turbo-studly? (Score:1)
--
Re: Where's "MNG"? (Score:1)
As others have noted, MNG [cdrom.com] is pretty much fully specified (and note that it includes a JPEG/PNG hybrid called JNG that provides transparency and gamma/color-correction to JPEG), but there is basically zero in the way of sample source code for it--and it is much more complex than PNG. On the plus side, Gerard Juyn has offered to make his MNGeye viewer code available as the starting point for a "libmng" implementation, but no one has had time to do anything with it yet. So those who are truly keen on sprite-based animation a la MNG can always get started and make life nicer for all of us.
In fairness, I should also note that Flash is in many respects competitive with MNG, and it includes some PNG-like support as well. So despite the fact that MNG includes some features not present in Flash, it may well turn out that Flash "wins" simply by virtue of being out there, being "open enough," and having several implementations (well, at least two, anyway).
Even if Flash becomes the de facto next-generation animation standard, I suspect that JNG will find favor, too. If you're already linking with libjpeg and libpng, adding support for JNG requires almost no additional code.
Re: Irony on their website (Score:1)
Correction: it's a GIF to you, presumably because you have a stupid (i.e., not conformant with HTML 4.0) browser. To anyone with a clueful browser, it's a PNG. Here's the source (which, of course, you could have looked at yourself):
<H5 ALIGN="center">
<A HREF="img_png/pnglogo-blk.jpg">
<OBJECT WIDTH="256" HEIGHT="192" TYPE="image/png"
DATA="img_png/pnglogo-blk-sml1.png">
<IMG WIDTH="256" HEIGHT="192" SRC="img_png/pnglogo-blk-sml1.gif"
ALT="[PNG: 256x192 colored-balls logo]"></OBJECT></A>
</H5>
The only general-purpose approach that guarantees a PNG image to most of the browsers capable of viewing them natively is content negotiation, something that requires direct access to the server (and also something that even Apache doesn't implement very elegantly). Did I mention that all current versions of Navigator have a bug in their implementation of client-side negotiation, a tiny bug that nevertheless means IIS servers will never send an embedded (that is, IMG-tagged) PNG image to them? Check out puzzlemaker.com [puzzlemaker.com], one of the better-known casualties.
But I will do my best to make sure Mozilla/Gecko has excellent PNG support. I have just one little detail to get out of the way first...
Re: Why make it an ISO/IEC standard? (Score:1)
The PNG spec, like the VRML 2.0 spec [web3d.org] before it, will remain freely available. The ISO will have the right to sell the version with their boilerplate and logo, but the technical content will be identical, and there will be no restrictions on the distribution of the W3C and PNG Development Group versions.
As for benefits: believe it or not, there are companies (and especially governments) that require the use of an international standard wherever possible. In the case of the US, it is often the case that companies wishing to do business under government contract must support the relevant standards in their products--and to the extent that this support is not seen as a complete waste of time and code, it generally ends up in the versions of the product that you buy, too.
ISO/IEC standardization is also seen as somehow better/safer than standardization promulgated by Internet upstarts like the W3C, IETF or PDG. Again, that may result in more and/or better support in your favorite products.
Of course, these things take time, and it looks like there will be another FCD and four-month voting period before PNG even makes it to the Draft International Standard stage, which itself lasts a good number of months. So it's pretty safe to say that there are no immediate advantages to all of this.
By the way, it's conceivable (though not definite) that zlib/deflate will be next. :-)
ISO / IEC for profit? (Score:1)
The issue is that, generally speaking, you can't post an ISO standard on the net. It's against the rules. The only way to get the doc is to pay ISO or the national standards body that is a member of ISO (ANSI in the US).
Now, it may be possible to get around this somehow, and negotiate an exception with ISO. But it is a reason to prefer the IETF process; IETF standards are made freely available.
Because TIFF = big (Score:1)
If I am wrong, I'm sure some AC will point it out.
No Subject Given (Score:1)
Mindless drivel. (Score:1)