How do I move an iDVD movie from DVD back to hard disk and start it from there?

Now that hard drive storage is relatively cheap, I'd like to transfer my iDVD movie projects from my DVD collection back onto my hard drive and be able to run them from that drive. Is "disk image" what I want? I've copied all the files from a DVD into a new folder on my hard disk, but there's no file in the AUDIO_TS or VIDEO_TS folders that will start up the movie. Would be grateful for any help. (I no longer have the original project files that I used to burn the DVD.)