

PHash - open source perceptual hash library. image/video fingerprints - albertzeyer
http://phash.org/

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SeppoErviala
I recently tried out pHash and it seemed to be a good tool for detecting
nearly duplicate images. Certainly superior to calculating md5 for images and
comparing those.

However, if the images have different cropping, slight rotation or different
brightness/contrast setting pHash didn't seem to work well enough. I got
better results with <http://www.imgseek.net/> for my image set.

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albertzeyer
I was searching for some methods to get a fingerprint for an image and this
was basically the only lib I found. Otherwise, most often, I got
recommendations about using OpenCV and collecting SIFT/SURF (and maybe other)
features - although I never saw a ready and working implementation.

An overview of some StackOverflow questions:
[http://stackoverflow.com/questions/4196453/simple-and-
fast-m...](http://stackoverflow.com/questions/4196453/simple-and-fast-method-
to-compare-images-for-similarity)

