I believe you can do what you describe (if I understand correctly) using just the current PDB. You will have to convert your image to Indexed Mode and then back to RGB in order to create the previews (as Andreas stated, you can only have 1-bit alpha when using using the GIMP's Indexed Mode).
Below you will find a link to a short Script-fu which I think provides close to what you want (or perhaps you might just otherwise gain some inspiration from it). You will have to provide your own code to save the Indexed version and the resulting layer mask (which is the N-bit Alpha channel), as well as create any miniaturized previews; the script is merely intended for demonstration of a technique. http://www.postbrickfilms.com/saulgoode/GIMP/Scripts/alpha-preview.scm _______________________________________________ Gimp-developer mailing list Gimp-developer@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer
