command/script for finding *non*duplicate files?

[Ralf Mardorf]

On Mon, 08 Feb 2016 15:29:35 +0000, Adam Funk wrote:
>...but that won't work because the files may have been renamed.

You could write loops that 'diff' each photo with each other photo.
Note, dash is faster than bash, 'case ... in' is faster than 'if'.
Perhaps it's much faster, if you just 'grep' some meta data of your
photos, provided by 'exiftool' and write loops that compare that data
of each photo.