title: Image Normalization for CNN
body: <p>I have seen multiple ways to normalize images before training them for a CNN.  One way I am thinking of going with is:</p>
  
  <pre><code>normalized = (gray - np.min(gray)) / (np.max(gray) - np.min(gray))
  </code></pre>
  
  <p>Is there an advantage to this approach vs the standard deviation approach?  Can the normalized image be returned to its original grayscale version (denormalized)?</p>