pHash (perceptual hash) for duplicates & similar

Ideas for improvements and requests for new features in XnView Classic

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Goulu
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Joined: Thu May 29, 2008 12:49 pm

pHash (perceptual hash) for duplicates & similar

Post by Goulu »

Hello,

I suggest indexing all images in the database by a "perceptual hash" . See here : http://www.hackerfactor.com/blog/?/arch ... ke-It.html it's extremely simple and fast. There is a library here to do it : https://www.phash.org/

I use it for a professional project and it's incredible : with a 32 bits key, you can instantaneously (well O(log N) ...) find duplicates in hundreds of thousands of images. And very quickly find similar images.

Since XnView already builds a database, I think this feature would make it the fastest duplicates and similar image finder on Earth. :D
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xnview
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Re: pHash (perceptual hash) for duplicates & similar

Post by xnview »

thanks, i'll check it
Pierre.
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m.Th.
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Re: pHash (perceptual hash) for duplicates & similar

Post by m.Th. »

m. Th.

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jadO
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Re: pHash (perceptual hash) for duplicates & similar

Post by jadO »

xnview wrote: Mon Oct 02, 2017 7:24 am thanks, i'll check it
Will that be built into XnViewMP?
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xnview
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Re: pHash (perceptual hash) for duplicates & similar

Post by xnview »

yes usefull, but to create it, i need to load image
Pierre.
jadO
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Re: pHash (perceptual hash) for duplicates & similar

Post by jadO »

xnview wrote: Tue Mar 16, 2021 3:15 pm yes usefull, but to create it, i need to load image
Is that a problem? From my understanding when a creating thumbnails, the image must be loaded too. So why not combining thumbnailing with hashing?
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xnview
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Re: pHash (perceptual hash) for duplicates & similar

Post by xnview »

jadO wrote: Fri Jul 30, 2021 7:51 am
xnview wrote: Tue Mar 16, 2021 3:15 pm yes usefull, but to create it, i need to load image
Is that a problem? From my understanding when a creating thumbnails, the image must be loaded too. So why not combining thumbnailing with hashing?
No, image is not always loaded, when embedded thumbnail is available or small preview
Pierre.