This script doesn't seem to work. Tried it on textures.rcru and got absolutely nothing extracted...said 0 files found and some gibberish, that's about it.
not to necro the thread or anything, but if that's what you saw instead of an error, then i suppose i could've made it clearer that there's a few lines at the bottom to uncomment in order to extract sprites (or texture slices as i call it in the script). i tested it again and it still works fine. i also have the extraction results here somewhere, but i don't know if it's up to date (don't have the game).
i changed the script so that it extracts raw slices by default, though like i wrote there, you'll need to convert those to png with something else. it contains extra code to invoke imagemagick as it goes through the textures, but besides uncommenting you'll have to adjust the line it's invoked in, if it's not on your PATH or something like that.