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PNG (image format) 1.1 spec released
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. "
Hey Rob? How much are your sponsors paying for that pretty gray-on-black "INTERNAL SERVER ERROR" in the top frame?
It helps that there is a free, standard
implementation of PNG so that it is easy
for programs to use. Other people have
noted PNG's compression advantages, and
the fact that there is a single standard.
The progressive-display features of PNG
are also nice for Web use.
Does TIFF have a gamma setting, an alpha channel, or good interlacing? (And does everything support them?) I see these as PNG's real advantages, at least over GIF (along with freedom from patents and truecolor). Also, PNG is so simple it has a shot at being mostly implemented, even in browsers.
(PNG:TIFF :: XML:SGML)
Wahoo. Does it implement PNG? No? Then go away!
What kind of idiot purposefully annoys potential volunteer testers by spamming them? Do you work for MS or something?
That's about the only reason why we still have t use GIFs.
everything, but no viewer implements it
interlacing and, more important, it's not streamable - the image data could be anywhere in
the file, loading a TIFF can involve lots of seek
operations, e.g. get image description at the
end of the file, then get image at the beginning
of the file - this way, a browser had to download the complete file before even knowing how the image resolution is
7.0 version of their specs will probably never come out as nobody there seems to care for it, while PNG has people working on it (library and specs)
know alpha and gamma, it even has support
for PNG's deflate compression algorithm and JPEG's
lossy compression algo, though nobody really supports it - as for libraries, there is libtiff, but I guess nobody does development on it;
the only compression algorithm widely supported in TIFF is LZW, which is the same as in GIF - deflate almost always beats it
image in a file by specifying proprietary tags in TIFF or adding text comments
CIE LAB etc.
TIFF, but only one in a PNG (e.g. for thumbnails)
People thought a bit about what a network image file format should have in it when designing it
and they didn't make the mistake to try to
integrate anything. TIFF also has some advantages,
but most of them don't matter for the net (e.g. CMYK support). OTOH, PNG has some nifty things in it TIFF doesn't, e.g. checksums everywhere.
Marco
Does anyone else find it ironic that the PNG logo on the PNG website is itself a GIF?
See http://www.cdrom.com/pub/mng/mngdocs.html.
Marco
Wasn't PNG developed to replace GIF because compuserve (and whoever owns the format with them) all of the sudden became bastards? I don't see why the logo isn't a jpeg...
There's a long history behind this submarine patent debacle. Sperry had the LZW patent, so now Unisys (spit) does. CompuServe waited a long time to warn everyone after they were told this is an issue, but otherwise this is really Welch's fault for publishing that article conveniently forgetting to mention the patent.
SGML is horrendously complex, even for an ISO standard. nsgmls (part of James Clark's excellent SP package) compiles to over a megabyte of x86 code- and it's just a parser.
IMHO specs like PNG that J.Random Hacker can sit down and actually implement correctly are far superior.
The PNG standard is pretty braindead if
it does not support animations.
I will not use it.
Is there any particular advantage to making PNG an
ISO/IEC standard? These standards are sold for
profit, and so the standard will not be freely
available if it goes ISO/IEC. So, why do it?
ISO/IEC/IEEE could post standards on their web page for free download. Cost to them: $1000/month for net access.
They could sell them for something approximating cost. The POSIX standard (~750 pages) sells for around $100. That's more per page than most computer books, which are definitely sold for profit.
So, work it out. It's profit. Especially if those who participate in the standards process get no revenue from the selling organization. Rather, the ISO pockets it all.
Who is Fastest?
nice little mess over 0.89 and 1.0 being incompatible...
hopefully this one will help to fix that (or at least have a different name for the compiled lib when they release that)
- 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.
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.)
I've been waiting for MNG (Multiple Network Graphics)
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.
So shouldn't we be adding it to GIMP, Mozilla, Imlib and others? Can you provide a URL?
How does this even resemble anything with content?
One benefit of PNG over TIFF, especially for WWW applications, is the turbo-studly seven-pass interlacing format.
:)
Kinda like the old GIF interlacing, except turbo-studly.
Excuse me?
--
Fuck the system? Nah, you might catch something.
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.
Even with compression, TIFF files are much larger than JPG or even PNG files.
If I am wrong, I'm sure some AC will point it out.
Free Mac Mini. Yes, I'm
Cool....
As I said...