[Michael P]

I would suspect that a little work would need to be done to the code as the calls to ImageMagick are not written as such to convert between one type to another. And since TGA files do not display in browsers, they would need to be downloaded as multimedia type files (which means just making TGA a multimedia type).

However, the default for multimedia types is to ask for a thumbnail during upload, so again that would also need to be changed.