I think it's good because it gives the format more versatility. JP2k has both lossy and lossless, even the old TIFF format has lossy JPG compression (although that seems completely stupid to me, due to the fact that the quality/fileesize ration of a TIFF with jpeg compression is much worse than a true JPG.)


I'd also love to see the APNG (animated PNG) format take off. It's supposed to make animated PNGs in the same manner as animated GIFs (which is vastly different from the existing MNG method). It is also partially compatible with programs that can read regular PNGs but not APNGs. Such a program will still display the first frame of the animation.

Edited by Cypherswipe at 22:30 on December, 22nd 2004

That's exactly what I don't like about it. The PNG format is widely known as lossless. Now this other 'version' comes along and topples this belief. Confusion galore.

You obviously only looked at the garfield images on the first page. Click the links for the game screenshots and for the phot with text.



Lossy PNG isn't truly a new format, it's merely an adaptation of an existing (and quite well supported (IE notwithstanding)) format.

Edited by Cypherswipe at 22:13 on December, 22nd 2004

Very badly chosen example images on that page. The losless PNG looks way better (no artifacts) and its file size is also smaller at the same time.

Anyway, it's indeed overdue that classic JPEG is replaced by something better, but I still don't see why it should be yet another new format (which, because of its name, would lead to confusion) and not just JPEG2000.

There are some projects going on to make a lossy version of the PNG format. Currently, none are very good, but the idea has a lot of potential. Imagine being able to have full color images with alpha transparency, yet have them only be about the size of a JPG. This can also get around the problem of what to do with an image that contains both detailed photographic type data and large areas of solid color (especially red). Currently you either have to have a JPG that makes the solid colors look crappy, an indexed PNG/GIF which makes the photographic part of the image look bad, or a true color PNG that has a massive filesize. (There are other formats such as JPG2000 that solve this issue, but they still have limited support. Lossy PNGs can be read by anything that can read regular PNGS.) The JNG format has these same qualities, but has virtually no support at all (a real shame).

The only program I've found that has a working implementation of the lossy PNG format is Image Analyzer by Meesoft. (There are some programs/libraries like pack4png, but they're designed for 256 color images. The lossy PNG format is intended for true color images.) The lossy PNG format used in Image Analyzer is a poor choice for indexed images since it usually winds up INcreasing their size, it works quite well on photographic images though (still larger than JPG, but much smaller than normal PNGs). Here's a page with some samples and links: http://allspark.net/cypherswipe/lossypng.html