FirmTools Duplicate Photo 

Duplicate Photo Finder is a program that finds duplicates and similar photos. Unlike most of its competitors, it does not rely only on a bit-by-bit comparison, but uses an algorithm to identify similar pictures, even with different sizes. During scan we can preview the duplicate already found in a double image screen, allowing us to visually confirm that the images are the same. The results screen shows the percentage of similarity, and we will find that low percentages are usually very similar photos with small differences.

The interface is very intuitive and it is very easy to begin searching for duplicate copies. There is an option to search the whole disk, or simply select some folders. On the down side, the comparison must be made for every file against every other file, and so, this can mean a long wait. Nevertheless, the application seems robust enough and does not take over all of the system resources, meaning we can just put it in the background while doing other work. That said, I was agreeable surprised with the time it took to search my 5500 small images collection.

There are several options on what to do with the duplicates: move, delete, or copy them (although only copy is available in the trial version). We can choose to look for rotated of flipped images and to ignore photos smaller than a specified size.

The new version contains the cache file corrupted bug fix, correctly handles photos that were deleted outside the application and fixes the Vista UAC (User Access Control) issue.