Maybe off-topic to your original need. But I've always wanted / needed a utility that can de-duplicate media (images, music, videos) that I have scattered around which are the same thing just at different qualities/resolutions.

I get that for music and video this is actually quite challenging but images - - I would've thought quite easy? I've tried a few tools which claim to do this over the years but they all fail rather miserably / require a paid upgrade to do it better (although what is demonstrated in the free version is never impressive enough to consider paying).

Might be a good project for myself in my spare time, but wondered if anyone knew of anything obvious I was missing? FSLint and stuff is great for general filesystem de-duping, this is a slightly more complex case.