Python's way of comparing the similarity between two images

This article illustrates how Python compares the similarity between two images. Share with you for your reference. Specific analysis is as follows:

This code USES pil module to compare the similarity between the two pictures. According to the practical application, the code is short, but the effect is good, and it is very reliable. The premise is that the picture is bigger, and the picture is not good for comparison if it is too small. The attachment provides the complete test code and pictures for comparison.

#!/usr/bin/python

# Filename: histsimilar.py

# -*- coding: utf-8 -*-

import Image

def make_regalur_image(img, size = (256, 256)):

    return img.resize(size).convert('RGB')

def split_image(img, part_size = (64, 64)):

    w, h = img.size

    pw, ph = part_size

    assert w % pw == h % ph == 0

    return [img.crop((i, j, i+pw, j+ph)).copy() 

                for i in xrange(0, w, pw) 

                for j in xrange(0, h, ph)]

def hist_similar(lh, rh):

    assert len(lh) == len(rh)

    return sum(1 - (0 if l == r else float(abs(l - r))/max(l, r)) for l, r in zip(lh, rh))/len(lh)

def calc_similar(li, ri):

#   return hist_similar(li.histogram(), ri.histogram())

    return sum(hist_similar(l.histogram(), r.histogram()) for l, r in zip(split_image(li), split_image(ri))) / 16.0

def calc_similar_by_path(lf, rf):

    li, ri = make_regalur_image(Image.open(lf)), make_regalur_image(Image.open(rf))

    return calc_similar(li, ri)

def make_doc_data(lf, rf):

    li, ri = make_regalur_image(Image.open(lf)), make_regalur_image(Image.open(rf))

    li.save(lf + '_regalur.png')

    ri.save(rf + '_regalur.png')

    fd = open('stat.csv', 'w')

    fd.write('n'.join(l + ',' + r for l, r in zip(map(str, li.histogram()), map(str, ri.histogram()))))

#   print >>fd, 'n'

#   fd.write(','.join(map(str, ri.histogram())))

    fd.close()

    import ImageDraw

    li = li.convert('RGB')

    draw = ImageDraw.Draw(li)

    for i in xrange(0, 256, 64):

        draw.line((0, i, 256, i), fill = '#ff0000')

        draw.line((i, 0, i, 256), fill = '#ff0000')

    li.save(lf + '_lines.png')

if __name__ == '__main__':

    path = r'testpic/TEST%d/%d.JPG'

    for i in xrange(1, 7):

        print 'test_case_%d: %.3f%%'%(i, 

            calc_similar_by_path('testpic/TEST%d/%d.JPG'%(i, 1), 'testpic/TEST%d/%d.JPG'%(i, 2))*100)

#   make_doc_data('test/TEST4/1.JPG', 'test/TEST4/2.JPG')

Complete sample code click here (link: http://xiazai.jb51.net/201503/yuanma/python-com-pic-codes (jb51.net). Rar).

I hope this article has helped you with your Python programming.