image to RGBA file

Hi guys!
I started using glut (with VS 2008) mainly for 2D applications.
I only draw sprites and even experienced with buffer swapping.

Now I want to add some sprites with transparency, how can I convert an image to a file with 4 values (R,G,B and A)?


paste in photoshop or other software
manage r g b a channels in photoshop

save as 32bit TGA file

Or you can try graphicsmagick/imagemagick for some quick command line work.

by manage you mean to add the alpha channel and then save it as a tga?