Advantages of PNG

Bill Bither likes the PNG format for graphics. In the start of his article, he lays out some of the nifty features that separate it from GIF and TIFF file formats. But there’s more.

“However, perhaps the best thing a PNG has to offer is what’s called the alpha channel. An alpha channel is one byte of extra data per pixel (or palette entry for 8-bit images) that represents the transparency level of a pixel. A PNG image with alpha is capable of 256 levels of transparency. What does all this mean? For one thing, you can antialias text and images so that sharp curves look good against any background. You can apply a true drop shadow which fades into the background. You can create images that take any shape or form. There are many possibilities with alpha transparency.
Browser Support

The unfortunate thing with alpha in PNG’s is that browser support is way behind the times, although slowly catching up. Although both Netscape 4.04+ and Internet Explorer 4.0+ both read PNG images, the windows version of MSIE 5.0 can only read one level of transparency in 8-bit PNG’s (the Mac version of MSIE5.0 works perfectly!). At least this allows for direct conversion of GIF’s to PNG’s. The good news is that the new Mozilla browser (the browser behind Netscape 6.0) fully supports PNG alpha. Microsoft should catch up very soon!”

See the examples and read the full article at Atalasoft’s web page.