dHash - perceptual image hash to find similar pictures

[KaFu]

dHash generates a “difference hash” for a given image - a perceptual hash based on Neal Krawetz’s dHash algorithm in this “Hacker Factor” blog entry.

http://www.hackerfactor.com/blog/index.php?/archives/529-Kind-of-Like-That.html

1. Reduce size
2. Reduce color
3. Compute the difference
4. Assign bits

The resulting hash value represents the relative change in brightness intensity. To compare two hashes, just count the number of bits that are different (called Hamming distance.)

A value of 0 indicates the same hash and likely a similar picture. A value greater than 10 is likely a different image, and a value between 1 and 10 is potentially a variation.

dHs - dHash_v0003.zip

Edited December 7, 2019 by KaFu

[UEZ]

Thanks for sharing. 

[haijie1223]

good job！mark！