png images

[Binky]

It seems like years and years ago I read about the superiority of png images for the web. Is anyone using them, yet? Do most browsers support png?

[PaulKroll]

1) Pretty much all browsers support PNG, but not all support it the same way and not all support it well.

2) Yes, some folks are using PNG, particularly those who simply hated the Unisys patent situation.

3) Since the majority of browsers handle GIFs more consistently, it's all moot.

It's annoying: I certainly think the Unisys GIF patent (actually a compression patent, no? I think that's the case, but it's been a few years since I cared enough to remember...) is Yet Another Atrocity commited by the PTO, which lets pretty much anything pass no matter how basic or irrational it seems. (One-click purchasing... great, thanks a bundle, that's just freakin' BRILLIANT there boys and girls... :( ) But I use GIFs and probably will for the forseeable future.

[Justin]

I use PNG wherever possible. If support was better I'd use them exclusively...

IE doesn't properly handle low color palettes from what I've seen, and Mozilla doesn't do small transparencies well (but the colors are perfect)... so if I need a very exact color, or if I need a 1x1 pixel transparent image, I use GIF, otherwise I use PNG.

I've seen both above behaviors with images created in Photoshop, Paint Shop, and the Gimp; I'm pretty sure it's a rendering issue in each case...

But all browsers handle GIFs perfectly, likely because they've been around plenty long enough for everyone to perfect the rendering...

[f2sys]

One thing PNG really works well for is importing anti-aliased or semi-transparent images into Flash or Director. Macromedia even uses a customized PNG framework as the native file format for Fireworks. I have not found enough consistency in the implementation of PNG support in even the most popular two browsers to warrant a full-scale switch to PNG format for my web graphics. An 8-bit PNG can be much smaller than an identical GIF but the 24-bit version (although lossless) will be larger than a JPEG. PNGs don't support animation like GIFs but a PNG variant called MNG does.

BTW: The Unisys patent was on LZW (Lemple-Zif-Welch) compression encoding. The same lossless technique can be used in TIFF files. If you own a registered copy of graphic editing software like Photoshop whose manufacturer paid the LZW licensing fee then there's probably no issue. If you use some free or shareware, it's very unlikely, but you may be prosecuted.

If you have time, visit:
http://burnallgifs.org/
They're still pretty hoppin' mad over there. And though I agree with them, I still use GIFs.

[janderk]

Originally posted by Binky:
It seems like years and years ago I read about the superiority of png images for the web. Is anyone using them, yet? Do most browsers support png? They pop up more and more. They are better than gifs because of the gif licensing issues and because gif's limitation of max 256 colors.

Although for picture type images most people will keep on using JPEG's because the file size is much smaller. JPEG's are lossy while PNG's are lossless but a normal human generally does not notice the difference.

JD