color_dHash192.py

'''
Script for computing the 192-bit Difference Hash of color RGB Images.
Usage: python color_dHash192.py <image path>
'''
from __future__ import print_function
import sys
from PIL import Image
import numpy as np

import imagehash ## https://github.com/JohannesBuchner/imagehash

imagepath = sys.argv[1]

def color_dhash(imagepath):
    
    im = Image.open(imagepath)
    npim = np.asarray(im)
    
    imr = Image.fromarray(npim[:,:,0])
    img = Image.fromarray(npim[:,:,1])
    imb = Image.fromarray(npim[:,:,2])
    
    hashr = bin(int(str(imagehash.dhash(imr)), 16))[2:]
    hashg = bin(int(str(imagehash.dhash(img)), 16))[2:]
    hashb = bin(int(str(imagehash.dhash(imb)), 16))[2:]
    
    gapr = 64 - len(hashr)
    gapg = 64 - len(hashg)
    gapb = 64 - len(hashb)
    
    hashrf = ''.join(['0' for i in range(gapr)])
    hashgf = ''.join(['0' for i in range(gapg)])
    hashbf = ''.join(['0' for i in range(gapb)])
    
    hashrf += hashr
    hashgf += hashg
    hashbf += hashb

    im.close()
    
    return str(hex(int(hashrf + hashgf + hashbf, 2)).split('0x')[1].split('L')[0])

    
if __name__ == '__main__':
    if len(imagepath) != 0:
        print(color_dhash(imagepath), imagepath)
    else:
        print('Bad path.')