"Reader Rob J recommended Unique Filer as a solution to helping eliminate duplicates. The software scans files for both exact match duplicates, as well as images of different sizes and composition, even if they aren't truly identical. This last option, referred to as Fuzz Compare, examines the makeup of images looking for similarities. A tree listing of results includes thumbnails of images for a visual set of results. There's a power user feature to auto delete duplicate files, but it's off by default. I haven't spent tons of time with the app as of yet, but I have tons of similar images and Unique Filer impresses me with the results I've seen so far. There is a beta version of v2.0 still in progress for the past 5 years, but the 1.4 version seems quite effective. The trial version is fully functional but nags to register on startup and after every 10 deleted files."You can
download the software here. It seems like a nifty tool but I have found it easier to delete pictures as I go. This is probably more so because I just dump my pictures into a folder on my server and don't touch them for a while. This way if I eliminate the pictures I wouldn't want as I go then it would be fewer images just sitting around.