title: NumPy, PIL adding an image
body: <p>I'm trying to add two images together using NumPy and PIL. The way I would do this in <a href="http://en.wikipedia.org/wiki/MATLAB" rel="noreferrer">MATLAB</a> would be something like:</p>
  
  <pre><code>&gt;&gt; M1 = imread('_1.jpg');
  &gt;&gt; M2 = imread('_2.jpg');
  &gt;&gt; resM = M1 + M2;
  &gt;&gt; imwrite(resM, 'res.jpg');
  </code></pre>
  
  <p>I get something like this:</p>
  
  <p><a href="http://www.deadlink.cc/matlab.jpg" rel="noreferrer">alt text http://www.deadlink.cc/matlab.jpg</a></p>
  
  <p>Using a compositing program and adding the images the MATLAB result seems to be right.</p>
  
  <p>In Python I'm trying to do the same thing like this:</p>
  
  <pre><code>from PIL import Image
  from numpy import *
  
  im1 = Image.open('/Users/rem7/Desktop/_1.jpg')
  im2 = Image.open('/Users/rem7/Desktop/_2.jpg')
  
  im1arr = asarray(im1)
  im2arr = asarray(im2)
  
  addition = im1arr + im2arr
  
  resultImage = Image.fromarray(addition)
  resultImage.save('/Users/rem7/Desktop/a.jpg')
  </code></pre>
  
  <p>and I get something like this:</p>
  
  <p><a href="http://www.deadlink.cc/python.jpg" rel="noreferrer">alt text http://www.deadlink.cc/python.jpg</a></p>
  
  <p>Why am I getting all those funky colors? I also tried using <code>ImageMath.eval("a+b", a=im1, b=im2)</code>, but I get an error about RGB unsupported.</p>
  
  <p>I also saw that there is an <code>Image.blend()</code> but that requires an alpha.</p>
  
  <p>What's the best way to achieve what I'm looking for?</p>
  
  <p>Source Images (images have been removed):</p>
  
  <p><a href="http://www.deadlink.cc/_1.jpg" rel="noreferrer">alt text http://www.deadlink.cc/_1.jpg</a>
  <a href="http://www.deadlink.cc/_2.jpg" rel="noreferrer">alt text http://www.deadlink.cc/_2.jpg</a></p>
  
  <p>Humm, OK, well I added the source images using the add image icon and they show up when I'm editing the post, but for some reason the images don't show up in the post. </p>
  
  <p>(images have been removed) 2013 05 09</p>