How does Photo Deduplicator work?

Photo Deduplicator takes a number of photo files (i.e. JPEG, PNG, TIFF, GIF, RAW, etc.) as input and analyses their associated metadata containing information like date and time the picture was taken, as well as the picture itself, to determine duplicate photo files. It then allows you to select photo files for removal, i.e. "trashing" them into the Mac's bin or moving them to a selectable output folder of your choice.

To allow you to easily select which photo files you want to remove, Photo Deduplicator groups them based on certain criteria. There are three kinds of grouping criteria supported:

1. Group identical photo files: Identical photo files means photo files that are byte-wise identical, i.e. exact copies of each other.
2. Group related photo files based on timestamps: Here photo files which have a timestamp that is not further apart than a selectable threshold are grouped together. This option allows you to easily group photo files that were all taken within a certain time window, e.g., an hour.
3. Group similar photo files based on timestamps and image content: This option finally compares photo taken within a certain time window and which have content that is not necessarily identical, but sufficiently similar (e.g. several similar portraits taken of a person with slighthly different perspective or facial expression). You can to some extent determine the level of similarity required for photos to be grouped together.

   Caveat: Determining whether two photos are similar is not a straightforward task and the algorithm applied allows for a fair amount of error. Before trashing photo files ensure that you have double-checked what you selected!

Photo Deduplicator will never overwrite an existing file (e.g. "Photo.jpg") in the output folder, if you have chosen one as the target for trashing files. Instead, it will add a sequence number to the end of filename it tries to create (e.g. "Photo 02.jpg")

Photo Deduplicator can take millisecond information of time stamps properly into account when sorting photos by time.