You got it. No misunderstanding. Images are on the client side and the web-app needs them on the server side in order to be associated with data in the form. The idea of having a client app to upload images is interesting. I'll look for it.
Some friend sent me this advice for the problem: "webdav"; but for me it is just a buzzword :) . I'll investingate this webdav too. Thanks for your help! Emanuele