php image manipulation transparent png or swf

I am in need of a script that will take an uploaded jpg file and set a certain color(range of that color) and then turn that file into a png or swf file with transparency(would prefer the swf). I would like the user to pic a color and the script would then make that color transparent. I already have the upload script. Please let me know of any other way to accomplish this? toad ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Installation package that will install the software (in ready-to-run condition) on the platform(s) specified in this bid request. 3) Exclusive and complete copyrights to all work purchased. (No GPL, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site). ## Platform windows