title: How to paste an image onto a larger image using Pillow?
body: <p>I've got a fairly simple code file:</p>
  
  <pre><code>from PIL import Image
  til = Image.new("RGB",(50,50))
  im = Image.open("tile.png") #25x25
  til.paste(im)
  til.paste(im,(23,0))
  til.paste(im,(0,23))
  til.paste(im,(23,23))
  til.save("testtiles.png")
  </code></pre>
  
  <p>However, when I attempt to run it, I get the following error:</p>
  
  <pre><code>Traceback (most recent call last):
      til.paste(im)
    File "C:\Python27\lib\site-packages\PIL\Image.py", line 1340, in paste
      self.im.paste(im, box)
  ValueError: images do not match
  </code></pre>
  
  <p>What is causing this error? They are both RGB images, the docs don't say anything about this error.</p>