Find duplicate photos: Two utilities that can help
When it comes to photos, there's no one definition of the word duplicate. Obviously, if two JPG files are pixel-by-pixel, bit-by-bit identical, they're duplicates, and you can safely delete one of them. But what if one photo has been resized Or cropped Or color-corrected Or what about very similar photos taken with your camera's multi-shot mode
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The last time I discussed duplicate files, I recommended Duplicate Cleaner, which comes in a limited free version and a much more powerful $30 Pro version. How they handle photos is a major difference between the two.
The free version doesn't really treat photos as photos, but simply as files filled with 1s and 0s. If you have two copies of the same photo, bit-by-bit identical, the program will find them. This is a quick and convenient way to get rid of duplicates for which there is no ambiguity.
Duplicate Cleaner Free has a few other tricks. You can change the settings so the program will ignore content and look for files with the same name and/or creation date. But that's about it.
The pro version has a powerful Image Mode (grayed out in the free one). This will help you group images that have been cropped, rotated, or resized. You can set how similar the images are by percentage.
But my current tool for this job is the Free Duplicate Photo Finder. Like Duplicate Cleaner Pro, it can find photos that have been altered in various ways, as well ones that simply look alike.
Photo Finder sports a wonderful user interface for this job. Once the scan is done, it displays matching photos side-by-side, along with a "Similarity" percentage--so you can look at two photos and make your decision.
A few things worry me about Free Duplicate Photo Finder. As near as I can tell, it hasn't been updated since December, 2013. It doesn't display a version number. And when I emailed the contact number, my message bounced.
I can find nothing wrong with this program. None of my scans found malware. It doesn't attempt to install PUPs. It appears to be completely clean, but it's an orphan, no longer supported, and some people may be uncomfortable using it.