Page 1 of 1

pHash (perceptual hash) for duplicates & similar

Posted: Fri Sep 29, 2017 2:55 pm
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

Re: pHash (perceptual hash) for duplicates & similar

Posted: Mon Oct 02, 2017 7:24 am
by xnview
thanks, i'll check it

Re: pHash (perceptual hash) for duplicates & similar

Posted: Mon Jan 29, 2018 7:29 am
by m.Th.

Re: pHash (perceptual hash) for duplicates & similar

Posted: Sat Jul 21, 2018 5:36 am
by jadO
xnview wrote: Mon Oct 02, 2017 7:24 am thanks, i'll check it
Will that be built into XnViewMP?

Re: pHash (perceptual hash) for duplicates & similar

Posted: Tue Mar 16, 2021 3:15 pm
by xnview
yes usefull, but to create it, i need to load image

Re: pHash (perceptual hash) for duplicates & similar

Posted: Fri Jul 30, 2021 7:51 am
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?

Re: pHash (perceptual hash) for duplicates & similar

Posted: Fri Jul 30, 2021 8:50 am
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