Application to find duplicated pictures compared by content

I piled up a lot of wallpapers and there are a lot of duplicates. I mean the same picture, but different aspect ratio, different resolution, quality, one with some text on it, the other without, etc …
So I wonder if somebody knows a program which compares images by content and shows me the similar ones. Back in the days I had something under Windows, something trial, but I don’t know the name to use it under wine and I can’t find with google.
So if somebody knows such an app, pls tell me about, be it native linux, be windows, I don’t care, just be free


gqview aka geeqie has a find dups function, not sure how well it works, haven’t used it much. Apparently gwenview and digikam can do it too. And a search shows an older thread about this. Good luck.

Tool to find duplicate images?

picassa does dups

Thank you!