non valid image format

[Madness]

I dont know if this is the right forum or not but I need something that will make my online photos copy proof.
Im not talking about "no right clik" scripts but something I came across a while back. I tried to copy an image and it was transfered to my HD normally but when I tried to open it I got a message "image format not valid etc."
How do I do that? watermarks? scripts?

[rock]

This topic has come up a number of times in this forum. You might want to try searching for previous threads, but if I recall, there's never been a sure-fire easy way to do this. The most tamper-proof way would be to show the images in a Java Applet. But you can never get around someone taking a screenshot of their screen while your page is up. Marking the images with watermarks and/or copyright notices should be done no matter what method you choose - but these won't add physical copy protection.