It would be great if picard were smart enough not to create duplicates of a particular cover art image if that image already exists in the destination location (folder) with a different name.

When I scan cover art, I name my cover art where the image type is part of the filename (in the form "Cover_<type>".  If I upload that image to MusicBrainz, then when I update the tags on an album, I usually end up with duplicate files, because picard saves new copies of them even though that exact image already exists in the album directory.

Perhaps there could be an option added like "Do not save duplicate images if image already exists with another name".  Whenever a cover art image is about to be saved, it would first scan any files that exist in the destination with the same size, and do a binary compare against the image it is about to save.  If it finds any file that is identical to the image to be saved, then it wouldn't save it again.