phash
This is a Haskell library
to detect (potential) duplicate images.
It also contains a command-line tool.
Use
Use it on one or more directories:
phash ~/Pictures ~/Downloads
~/Pictures/frog.jpeg, ~/Downloads/frog.png
Installation
Pre-Built Release
For many platforms, you can find binaries here.
Source
Download cabal-install and
GHC. Then:
cabal install perceptual-hash --constraint='hip +disable-chart'
Library
You can find library documentation on
Hackage.
This library has performs better on WebP, AVIF images and worse on JPEG images compared to the pHash library.
benchmarking fileHash/cat.png
time 21.50 ms (21.23 ms .. 21.70 ms)
1.000 R² (0.999 R² .. 1.000 R²)
mean 21.54 ms (21.39 ms .. 21.88 ms)
std dev 525.3 μs (224.2 μs .. 946.8 μs)
benchmarking fileHash/frog.jpeg
time 21.33 ms (20.57 ms .. 22.01 ms)
0.997 R² (0.996 R² .. 0.999 R²)
mean 19.84 ms (19.53 ms .. 20.24 ms)
std dev 822.7 μs (654.3 μs .. 1.070 ms)
variance introduced by outliers: 13% (moderately inflated)
benchmarking fileHash/frog.png
time 12.31 ms (11.88 ms .. 12.66 ms)
0.997 R² (0.994 R² .. 0.999 R²)
mean 12.46 ms (12.34 ms .. 12.58 ms)
std dev 314.3 μs (256.0 μs .. 385.0 μs)
benchmarking fileHash/liz-taylor.webp
time 69.02 ms (68.00 ms .. 70.23 ms)
0.999 R² (0.997 R² .. 1.000 R²)
mean 71.69 ms (70.28 ms .. 74.98 ms)
std dev 3.688 ms (1.345 ms .. 6.107 ms)
variance introduced by outliers: 16% (moderately inflated)
benchmarking fileHash/liz-taylor.png
time 72.32 ms (70.35 ms .. 74.49 ms)
0.998 R² (0.996 R² .. 1.000 R²)
mean 73.83 ms (72.60 ms .. 75.38 ms)
std dev 2.414 ms (1.655 ms .. 3.614 ms)
benchmarking fileHash/fashion.png
time 142.0 ms (131.6 ms .. 153.4 ms)
0.997 R² (0.991 R² .. 1.000 R²)
mean 145.8 ms (142.0 ms .. 153.9 ms)
std dev 7.690 ms (2.694 ms .. 11.43 ms)
variance introduced by outliers: 13% (moderately inflated)
benchmarking fileHash/fashion.avif
time 172.2 ms (161.5 ms .. 187.6 ms)
0.996 R² (0.991 R² .. 1.000 R²)
mean 175.1 ms (169.3 ms .. 185.3 ms)
std dev 12.16 ms (5.052 ms .. 18.42 ms)
variance introduced by outliers: 13% (moderately inflated)
benchmarking foreignHash/cat.png
time 21.06 ms (20.88 ms .. 21.19 ms)
1.000 R² (0.999 R² .. 1.000 R²)
mean 20.94 ms (20.80 ms .. 21.06 ms)
std dev 320.2 μs (225.5 μs .. 418.3 μs)
benchmarking foreignHash/frog.jpeg
time 9.255 ms (9.168 ms .. 9.378 ms)
0.999 R² (0.999 R² .. 1.000 R²)
mean 9.234 ms (9.201 ms .. 9.273 ms)
std dev 94.68 μs (79.14 μs .. 120.7 μs)
benchmarking foreignHash/frog.png
time 10.37 ms (10.28 ms .. 10.47 ms)
0.999 R² (0.999 R² .. 1.000 R²)
mean 10.42 ms (10.37 ms .. 10.48 ms)
std dev 135.4 μs (106.5 μs .. 184.9 μs)
benchmarking foreignHash/liz-taylor.webp
time 368.7 ms (352.4 ms .. 391.1 ms)
1.000 R² (0.999 R² .. 1.000 R²)
mean 362.3 ms (357.6 ms .. 366.4 ms)
std dev 5.133 ms (1.154 ms .. 6.530 ms)
variance introduced by outliers: 19% (moderately inflated)
benchmarking foreignHash/liz-taylor.png
time 71.58 ms (71.12 ms .. 72.03 ms)
1.000 R² (1.000 R² .. 1.000 R²)
mean 71.84 ms (71.66 ms .. 72.24 ms)
std dev 502.0 μs (339.8 μs .. 710.2 μs)
benchmarking foreignHash/fashion.png
time 162.1 ms (160.6 ms .. 162.8 ms)
1.000 R² (1.000 R² .. 1.000 R²)
mean 163.4 ms (162.9 ms .. 164.3 ms)
std dev 990.0 μs (544.6 μs .. 1.476 ms)
variance introduced by outliers: 12% (moderately inflated)
benchmarking foreignHash/fashion.avif
time 705.5 ms (669.6 ms .. 757.2 ms)
0.999 R² (0.998 R² .. 1.000 R²)
mean 716.4 ms (710.3 ms .. 728.3 ms)
std dev 11.54 ms (1.129 ms .. 13.84 ms)
variance introduced by outliers: 19% (moderately inflated)
Foreign Library
This package contains a foreign library and a header
file
ATS Bindings
Because of the foreign library, hs_phash can be used in ATS as well. ATS users
of the library may be interested in hs-bind.
