These images, unlike many of the others on this site, are full 32-bit RGBA PNGs (i.e., not palette-based). Some browsers, such as WebTV, may handle these better than indexed images.
This image is by Anthony Atkielski. It has basic, multi-level transparency: the outer parts are completely transparent, the text is completely opaque, and each region bounded by circles has one of three levels of (constant) partial transparency.
This lovely image was created by Diana Todd using various 2D and 3D tools, including Paint Shop Pro; it's available from her Free Tubes site (Scenes category), along with more than 3800 other PSP tubes in PNG format. The globe has varying levels of transparency, and the legs of the stand are antialiased.
This pair is from Willem van Schaik's AlphaMix program (for Windows), which allows one to composite alpha-PNGs against other images or against a checkered background. Any quantization of alpha levels by the browser (as in at least some versions of WebTV) should be quite apparent on the smooth, radial alpha channels of these images.
Here's a new rendering of the classic PNG logo, this time using POV-Ray 3.5 (beta 10), which finally can produce images with real alpha transparency. Greg banged this out in a couple of hours spread over a few days, and it shows--the ``PNG'' letters could use more contrast and ideally an internal glow (a la VRML's emissive property) in place of the iridescence in order to look good on any background. But this is good enough for now...
Here are some other pages at this site with PNG images:
Copyright © 1999-2009 Greg Roelofs.