Scenario: Burger business holds an online photo contest that gives $1 off on a hamburger meal, to anyone submitting a photo of themselves, wearing printed t-shirt with a burger on it.
Is there a way to identify if a photo was used before. The objective would be to have thousands and thousands of separate hamburger t-shirt pictures but no two pictures that are alike.
Wouldn't care what kind of burger as long as it is on the tshirt
This is not really a photography question. It is possible to do such things, but it is really a software engineering and artificial intelligence problem that has little to do with photography by itself.
I would suggest starting your research by looking at PhotoDNA, which is what a lot of websites use to detect images that they do not allow on their platform.
In photography, as long as each person takes a new photo, even if it is of a similar subject, it is still a new photo and the photographer cannot be faulted for repeating the content! As a business owner and issuer of the call, you must place a specific and variable physical sign on the objects in front of the lens when staging the scene for photography, so that no two photos are alike.
