Well, I found it .. sorta.
When using Adobe ImageReady there is a checkbox for transparency in the
optimize tab. Next to that there is a dropdown menu labeled "matte" You
can select from a variety of things like foreground color, background
color, white, black, Netscape grey, 50% grey, etc.
Now this is where it gets cool. When you save an image with transparency
it adds the "Matte" color into the anti-alias so things blend smoothly.
Fig1. Screengrab showing an example of Matte
http://obscura.obscurasite.com/images/screengrabs/matte.png
You set your "Matte" to the background color of your web page and you get
great looking transitions.
Every time I write a post to gimp-usr or gimp-devel I wondor if the
functionality is already in the gimp... and it usually is, but I didn't
know where to find it.
Here goes...
How do you control the "Matte" when saving images with alpha in the Gimp?
Thanks in advance.
--
Jon Winters http://www.obscurasite.com/
"Everybody loves the GIMP!"
http://www.gimp.org/