Hi mtiede – Please forgive the plug: Our TWAIN developer library includes a utility called ‘Twirl’ that makes it easy to examine all the ‘capabilities’ of a TWAIN device. If your camera is providing the filename of an image, offering it as the value of a capability would be the simplest technique. You don’t have to license our library to use Twirl, it’s part of the free toolkit download and it keeps working even after the trial period expires.
Deleting files from the camera: You are wrong in theory but I think right in practice. TWAIN has a whole ‘filesystem’ feature that in theory would allow you to examine the filesystem of the camera, and do all the usual stuff to files – get their names, rename them, delete them. The little problem is that I have never heard of this being implemented by any camera vendor… or actually, by anybody except Kodak.
Have you looked at WIA? It is much more camera friendly – but basically limited to Windows XP and ME. Still – that’s less of a limitation every day that goes by.