The only solution that I ever heard of that might be really effective was one that required anyone viewing the image th have a browser plug-in. It encrypted the image before it even hit the display adapter. It was one of those places where they don't list the price upfront. Anything that worked perfectly would be too expensive for the average person to use. Even those with one of the best deterrents of theft, a staff of lawyers, still has to use them regularly.

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken