How can I find duplicates of photos I renamed?

[oxband]

So, I just realized that I have lots of duplicates of photos I had on my computer, renamed and then saved to my external hd.

is there a way I can search my photos and find duplicates even if they have a different name? I imagine there is a simple little program that probably does this not just for photos but for any kind of file that's a duplicate. I just dont know what it is.

thanks!

 

[benwiggy]

If the file name is different, then it is quite hard to tell if files are duplicates.

Comparing every byte in each file against every byte in every other file is quite intensive.
One can compare file sizes, for starters, and list any two files that have the same size.

I doubt there is an app that would do this. However, this is something that could be done in shell scripting, by stages.