[dev] PNG alpha transparency with IE

[Etienne Goyer]

On Fri, Dec 05, 2003 at 01:37:26PM +0100, Daniel Eckl wrote:
> I love the possibility of those themes in horde, but they got me into a problem.
> I need a logo in the upper left, and it needs transparency. But since the
> background color can change through the themes, I need alpha transparency using
> png.
> 
> But as many of you know, IE 5.5+ is only able to view this alpha with a rather
> dirty css parameter.

IE does not indeed support PNG alpha channel, but it *DOES* support 
indexed PNG with transparency (aka PNG8 by some).  This is equivalent to
GIF with regard to transparency.

In The Gimp, open your PNG, Right click -> Image -> Mode -> Indexed.
You can then make some color transparent, and it will be interpreted
correctly by any version of IE I know of.

-- 
Etienne Goyer                    Linux Québec Technologies Inc.
http://www.LinuxQuebec.com       etienne.goyer at linuxquebec.com