[Group similar images] Group similar images using phash algorithm #python #image #algorithm #tools

group-same-image.py

"""
This script use to group similiar images from source folder
and save to the same output folder, base on the perceptual hash algorithm.
Work on Python3.6 and win10-build-17074
Prerequest: Pillow
Author: jferroal@gmail.com
"""

import hashlib
import mimetypes
import os
import shutil
from PIL import Image

Default_Resize_Width = 80 
Default_Resize_Height = 80 
Same_Image_Value = 600

def get_images_name(dir):
    """
    Get all images filename and file path in given directory
    :param dir: input directory to get images
    :return: filenames
    :rtype: a list of tuple(filename, file_path)
    """
    filenames = list()
    for f in os.listdir(dir):
        content_type = mimetypes.guess_type(f)
        
        if content_type[0] and not content_type[0].startswith('image'): continue
        file_path = os.path.join(dir, f)
        if os.path.isfile(file_path):
            filenames.append((f, file_path))
    return filenames

def get_gray_scale_image_data(path, resize_width=Default_Resize_Width,
        resize_heith=Default_Resize_Height):
    """
    Get gray scale image data in given path
    :param path: The image source path
    :param resize_width: After read image resize width
    :param resize_height: After read image resize height
    :return: image data
    :rtype: http://pillow.readthedocs.io/en/latest/reference/Image.html#PIL.Image.Image.getdata
    """
    im = Image.open(path)
    smaller_image = im.resize((resize_width, resize_heith))
    grayscale_image = smaller_image.convert('L')
    return grayscale_image.getdata()

def hash_image(path, resize_width=Default_Resize_Width,
        resize_heith=Default_Resize_Height):
    """
    Hash given image in path
    :param path: The image source path
    :param resize_width: After read image resize width
    :param resize_height: After read image resize height
    :return: integer hash value
    """
    hash_string = ""
    pixels = list(get_gray_scale_image_data(path, resize_width, resize_heith))
    for row in range(1, len(pixels) + 1):
        # compare the grey in same row
        if row % resize_width:
            if pixels[row - 1] > pixels[row]:
                hash_string += '1'
            else:
                hash_string += '0'
    return int(hash_string, 2)

def difference_hash(dhash1, dhash2):
    """
    Calculate the difference of two image hash
    :param: dhash1: image hash value 1
    :param: dhash2: image hash value 2
    :return: 1 count
    """
    return bin(dhash1 ^ dhash2).count('1')


class ImageToGroup(object):
    """
    Image to group class
    """
    def __init__(self, filename, path):
        # image hash value
        self.hash = hash_image(path)
        # image original path
        self.path = path
        # image filename
        self.filename = filename
        # image path(for saving grouped image)
        self.hash_path = hashlib.md5(str(self.hash).encode()).hexdigest()
        # parent image ref
        self.root = None

    def is_same_group(self, i2):
        return difference_hash(self.hash, i2.hash) < Same_Image_Value

    @property
    def root_rpath(self):
        # get image root path, if self is root, get self path
        if not self.root: return self.hash_path
        return self.root.hash_path

    def create_root_dir(self, base):
        # create directory if not exists
        if not os.path.exists(os.path.join(base, self.root_rpath)):
            os.makedirs(os.path.join(base, self.root_rpath))

    def copy_to_root_dir(self, base):
        # copy image from source to root directory
        print(os.path.join(base, self.root_rpath, self.filename))
        shutil.copyfile(self.path, os.path.join(base, self.root_rpath, self.filename))

    def copy(self, base):
        # do copy work
        self.create_root_dir(base)
        self.copy_to_root_dir(base)


class Groupter(object):
    """
    Do the group work
    """
    def __init__(self, images_to_group):
        self.images_to_group = images_to_group

    def group(self):
        # group all image
        for i in range(0, len(self.images_to_group)):
            for j in range(i + 1, len(self.images_to_group)):
                i1 = self.images_to_group[i]
                i2 = self.images_to_group[j]
                if not i1.root and i1.is_same_group(i2):
                    i2.root = i1
        return self

    def dump_group(self, path):
        # save all grouped images
        for image in self.images_to_group:
            image.copy(path)

    def remove(self, path):
        for image in self.images_to_group:
            if not image.root:
                shutil.copyfile(image.path, os.path.join(path, image.filename))


def main(indir, odir, action='group'):
    # main entrypoint
    # first, get all images
    filenames = get_images_name(indir)
    # second, using images to create imagesToGroup and initilize groupter
    groupter = Groupter([ImageToGroup(f[0], f[1]) for f in filenames])
    # do group and do save
    groupter.group()
    if action == 'group':
        groupter.dump_group(odir)
    else:
        groupter.remove(odir)

if __name__ == '__main__':
    import sys
    images_dir = sys.argv[1]
    output_dir = sys.argv[2]
    action = sys.argv[3]
    main(images_dir, output_dir, action)

How to use:

python group-same-image.py "/images/dir" "/grouped/to/save"  

How to use:

python group-same-image.py "/images/dir" "/grouped/to/save"  

python group-same-image.py "/images/dir" "/grouped/to/save" group