Here is what Photoshop Help says about PNG:
Developed as a patent-free alternative to GIF, the Portable Network Graphics
(PNG) format is used for losslessly compressing and displaying images on the
World Wide Web. Unlike GIF, PNG supports 24-bit images and produces
background transparency without jagged edges; however, some older versions
of Web browsers may not support PNG images.
I don't know a whole lot more about it. Here are some links with additional
information (descriptions, images to test if your browser will display PNG,
extensive links and resources:
Hope that helps.
Denis M. Sweeney
Graphic Design Engineer
San Jose, CA
From: Karen Morrione [mailto:[log in to unmask]]
Sent: Tuesday, February 09, 1999 1:14 PM
To: [log in to unmask]
Subject: Who uses PNG?
Does anyone out there use PNG instead of GIF or JPG for web graphics? If so,
why? If not, why not? Anyone know which HTML editors and other web-specific
tools support it?
Senior Technical Writer