When I do a search on Google for, say, a painting of a girl with a book (search words: painting girl book), I get a lot of duplicates.
By “duplicates” I don’t mean the same photo, but rather different photos of the same painting.
Why is there no search mode that shows one representative photo of each unique subject? After all, people are rarely searching for a particular photograph of something. They are much more likely to be looking for a particular thing, rather than a particular image of that thing.
I don’t think this would be very difficult to implement. For many items, including paintings, answering the question “Do these two images represent the same thing?” seems well within today’s technology. It’s a task that, for example, David Lowe’s SIFT transform could easily handle.