How PhotoMove Detects Duplicate Photos
When you are backing up years of photos from different cameras, phones, and hard drives, duplicate files are unavoidable. But how does PhotoMove actually know if a file is a true duplicate? You have two choices for how strict you want the program to be:
Option 1: File Names Match
This is the fastest method. PhotoMove simply looks at the name of the file. If it finds a file named IMG_1234.jpg, and it sees another file named IMG_1234.jpg already sitting in your destination folder, it assumes they are identical duplicates.
- Edited Photos: You may have edited a copy of a photo (cropped it, fixed the lighting, or changed it to black and white) but kept the exact same file name in a different folder. If you only check file names, PhotoMove will think your edited version and the original version are the exact same photo. You could easily overwrite your edited masterpiece!
- Camera Rollover: Digital cameras eventually run out of numbers and start over. A photo named
IMG_1234.jpgfrom your 2015 vacation might be a completely different picture thanIMG_1234.jpgfrom your 2022 vacation.
Option 2: All Exif and Exact File Contents Match (The “Digital Fingerprint”)
This is the smartest, safest, and most accurate option. Instead of just looking at the file’s name (the “cover of the book”), PhotoMove opens the file and reads the actual data inside (the “pages”).
How it works: The “MD5 Hash”
PhotoMove uses a mathematical process called an MD5 Hash to generate a unique “digital fingerprint” for every single photo.
- If you have two identical copies of an unedited sunset photo, they will both generate the exact same fingerprint. PhotoMove knows they are true duplicates.
- If you edit a photo (even just a tiny crop or brightness adjustment), the file’s internal data changes. Even if it still has the exact same file name as the original, its fingerprint will now be completely different. PhotoMove will recognize it as a unique version and safely keep both.
- Even if you changed the name of one identical photo to
Sunset.jpgand the other toIMG_9999.jpg, the fingerprint test will easily recognize that they are the exact same picture.
💡 Why we recommend this option: By checking the digital fingerprint, PhotoMove guarantees with 100% certainty that a file is a true duplicate right down to the very last pixel. It takes slightly longer for the computer to read the file contents, but it guarantees you will never accidentally overwrite or skip a unique or edited photo just because of a naming coincidence.
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