Due to some limitation in the PNG support for Internet Explorer, I had to convert all my PNG images to GIF….Pfffff !
The PNG image format was designed to be a replacement for the GIF format, due to both copyright and design problems with GIF. However, the latest version of Microsoft Internet Explorer (MSIE) still does not have full and proper support for the image format, despite the fact that the whitepaper for MSIE 4, which can be read here, promised full support:
“While other browser manufactures include PNG support as a 3rd party option , Internet Explorer 4.0 provides native support for PNG.”
Full native support for PNG still has not been implemented in the Windows version of MSIE, despite the fact that MSIE for Mac and others browsers have full support, and it was promised to the users of MSIE for Windows over four years ago.
We, the undersigned, request that the developers of MSIE for Windows please implement full support for PNG images, for the following reasons:
The PNG format is superior to the GIF format: When the same image is saved in both PNG and GIF formats, in an editor with full and proper support for both formats, the PNG image is typically a smaller file size, is free from royalties, patents, and copyright restrictions that hinder the GIF format, and can use more than 256 colours – up to 48-bit colour.
The PNG format is a World Wide Web Consortium (W3C) recommendation: Microsoft has repeatedly stated their renewed commitment to web standards, so implementing full PNG support would be the next logical step in fulfilling this promise, especially since it was supposed to be implemented over four years ago.
The PNG format supports alpha transparency: Anybody who has designed images for use online knows the woes of trying to make that image appear smooth on any background. Some designers create different images to be used on different background colours, other designers simply leave the edges jagged, and still others just give their images a solid background. It’s a bad way to go, but it’s the only choice right now. Using PNG images with alpha transparency would eliminate all of these problems, and make the work of web designers a lot easier.
After ignoring requests on this issue for four years, we hope that you, the developers of Microsoft Internet Explorer for Windows, will take a step in the right direction, and show that you truly are committed to web standards.
Source: Proper PNG Support in Internet Explorer for Windows