Image::PHash looks really great for duplicate and mirrored image detection. The best I've seen so far is unfortunately not accessible via Perl. YOLO/darknet is pretty neat, but the rub comes down to creating training data. I found that "roboflow dot com" makes it about as straightforward as one can get. Problem is, it's very expensive. Maybe with enough experience with it there can be a "ready made" Perl solution. Alien::OpenCV exists but I don't think that's gonna get you what you want. YMMV.