title: ndimage.imread(image_file).astype(float) not working in PIL
body: <p>I'm trying to read an image file and using scipy ndimage and then trying to convert the corresponding image file as float ndarray. But its throwing exception:</p>
  
  <pre><code>File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/PIL/Image.py", line 512, in __getattr__
      raise AttributeError(name)
  AttributeError: __float__
  </code></pre>