title: How can I set the background of a transparent image to white, using PIL?
body: <p>I have a PNG image with transparent background and I want to resize it to another image, but with a white background instead of a transparent one. 
  How can I do that with PIL?</p>
  
  <p>Here is my code:</p>
  
  <pre><code>basewidth = 200
  img = Image.open("old.png")
  wpercent = (basewidth/float(img.size[0]))
  hsize = int((float(img.size[1]) * float(wpercent)))
  img = img.resize((basewidth, hsize), PIL.Image.ANTIALIAS)hsize = int((float(img.size[1]) * float(wpercent)))
  img.save("new.png")
  </code></pre>