I would like to be able to enter one or more wildcards for files that should not be used for comparison, such as th_* for thumbnail versions which I have in abundance in the same folders as their full-size versions.

I have a huge and complex folder tree that contains nearly half a million pictures. Half of those are regular jpgs and the other half are thumbnail versions which are prefixed with a single three-character prefix. I would like to be able to search for duplicates among the full size images while ignoring the thumbnails during the comparison process. It would be very nice if actions on the full size images (move, delete, rename, etc.) would also be carried out on the thumbnails.