title: How to read a raw image using PIL?
body: <p>I have a raw image where each pixel corresponds to a 16 bits unsigned integer. I am trying to read using the PIL Image.fromstring() function as in the following code:</p>
  
  <pre><code>if __name__ == "__main__":
      if (len(sys.argv) != 4):
          print 'Error: missing input argument'
          sys.exit()
  
      file = open(sys.argv[1], 'rb')
      rawData = file.read()
      file.close()
  
      imgSize = (int(sys.argv[2]), int(sys.argv[3]))
  
      # Use the PIL raw decoder to read the data.
      #   - the 'F;16' informs the raw decoder that we are reading a little endian, unsigned integer 16 bit data.
      img = Image.fromstring('L', imgSize, rawData, 'raw', 'F;16')
  
      im.save('out.png')
  </code></pre>
  
  <p>The PIL documentation informs that the first argument of the fromstring() function is 'mode'. However, looking at the documentation and googling I wasn't able to find details about what that argument really means (I believe that it is related to the color space or something like that). Does anyone knows where I can find a more detailed reference about the fromstring() function and what the mode argument means?</p>