dhash_collision_gen.py

from PIL import Image
import imagehash
import numpy as np

AVAL = 10

class DhashCollisionGen:
    @staticmethod
    def generate_collision(image, hash_size=8):
        # get the dhash of the image
        image_hash = imagehash.dhash(image, hash_size)
        iarray = np.asarray(image.convert("L").resize((hash_size + 1, hash_size), Image.ANTIALIAS))
        # build the array that'll become the colliding image
        # the first index is height, the second is the width (think y,x)
        # 0,0 is the top and left
        newimg_arr = np.zeros((hash_size, hash_size + 1))
        '''iterate through the hash'''
        # set the first element of every row to 128
        for i in range(hash_size):
            newimg_arr[i][0] = 128
        # iterate through the hash
        for hrow in range(hash_size):
            for hcol in range(hash_size):
                # if the imagehash in hrow,hcol is true, then
                if image_hash.hash[hrow][hcol]:
                    newimg_arr[hrow][hcol + 1] = newimg_arr[hrow][hcol] + AVAL
                else:
                    newimg_arr[hrow][hcol + 1] = newimg_arr[hrow][hcol] - AVAL
        timg = Image.fromarray(newimg_arr).convert("L").resize((hash_size + 1, hash_size), Image.ANTIALIAS)
        #pixels = np.asarray(timg)
        #timg.save('timg.jpeg', 'JPEG')
        return timg


goodhash = imagehash.dhash(Image.open('./blue_orange.jpeg'))
print(goodhash)
collision = DhashCollisionGen.generate_collision(Image.open('./blue_orange.jpeg'))
chash = imagehash.dhash(collision)
print(chash)
print(goodhash == chash)