title: Compare two images and highlight differences along on the second image
body: <p>Below is the current working code in python using PIL for highlighting the difference between the two images. But rest of the images is blacken.</p>
  
  <p>Currently i want to show the background as well along with the highlighted image. </p>
  
  <p>Is there anyway i can keep the show the background lighter and just highlight the differences.</p>
  
  <pre><code>from PIL import Image, ImageChops
  point_table = ([0] + ([255] * 255))
  
  def black_or_b(a, b):
      diff = ImageChops.difference(a, b)
      diff = diff.convert('L')
      # diff = diff.point(point_table)
      h,w=diff.size
      new = diff.convert('RGB')
      new.paste(b, mask=diff)
      return new
  
  a = Image.open('i1.png')
  b = Image.open('i2.png')
  c = black_or_b(a, b)
  c.save('diff.png')
  </code></pre>
  
  <p>!<a href="https://drive.google.com/file/d/0BylgVQ7RN4ZhTUtUU1hmc1FUVlE/view?usp=sharing" rel="noreferrer">https://drive.google.com/file/d/0BylgVQ7RN4ZhTUtUU1hmc1FUVlE/view?usp=sharing</a></p>