Duplicates that aren't

The best solution for finding and removing duplicate files.
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geecee
Posts: 1
Joined: Sat Feb 11, 2017 3:17 pm

Duplicates that aren't

Post by geecee »

I'm having a problem getting Duplicate Cleaner to accurately report duplicate images. As a test, I have a single folder with two images in it. The images are visually identical, but differ in their dpi. When I calculate their hash (md5 or sha-1) by hand I get different values. Also, the file sizes are slightly different (3.87 MB vs 3.86 MB). However, when I run an Image Mode search with Photo Similarity set to "Exact Match" (and no other options checked) the tool always tells me the files are duplicates. I see the same behavior no matter which Content Comparison Type I choose.

FWIW, the images are jpeg's and I'm running version 4.0.4 of Duplicate Cleaner.

Any ideas?
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DigitalVolcano
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Posts: 1717
Joined: Thu Jun 09, 2011 10:04 am

Re: Duplicates that aren't

Post by DigitalVolcano »

The 'Exact match' in image mode hashes just the image pixels. This hash is different from the file hash which can differ due to image tags, etc.
DPI is just an image tag, and doesn't necessarily mean that the images are different on a pixel level.

If you scan them in Regular mode you should get two different hashes.
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