Take the 2-minute tour ×  I would like to create an image from a
map, where each country is colored in a different color, where
the frontiers are in black, and in which each color except black
is fully transparent, while not losing the RGB information.  My
tools are The Gimp or anything installable on Linux, and small
scale programming (if I need to fully understand the png format,
I won't succeed).  My current image is perfect, except for the
transparency information. My current experiments with GIMP have
always resulted in RGB information being lost when exporting the
image to png or gif.  Any pointers? Thanks a lot.  share|improve
this question If alpha is 0 there is no RGB information in png
or gif formats. What you are asking is not possible. –  Scott
Jan 5 at 21:29 I wouldn't dare confront anyone on such matters,
as my knowledge is practically null; yet, I would like to ask
you if you are reasonably sure of that, or sure without a doubt,
so that I don't spend any more time on this trail of thought.
Than