yeah that would be a pretty near-immpossible program I think... I mean it would hafto compare the pic to like every image on neopets... Big oO
I know of algorithms for detecting the use of the cloning tool in images. Here is a non technical this wired article on it. If there is such a tool then it might just be a matter of fetching the neopet images and running it on a local collection. So long as it is accurate and fast enough to find a 15x15 pixel square before the contest is over you're in business. I'm sure there is already something that will spider/fetch the images from neopets. It could just be a matter of finding a clone detection tool. No or very little programming required.
That would still be extremely long, wouldn't it? One way is to compile the images from popular Mystery Pic locations, like background, caption contests, etc. Resize them so they take up less space, and look for similar color groupings that match the mystery pic. Could that be done with Scar? Hmm, probably not.
I think it could be done quite easily if it searched every image for one color in the mystery pic then searched the that list for the next color, then that list for the next, etc. At the very least it would significantly reduce the ones you would need to manually go through. Perhaps all the images could even be tagged with the hex code of every color in their pallet, that way it would be as simple as text searching through the tags.
That would be pretty much impossible. And the mystery pic prizes arent that great either. It aint worth it.