title: Error when transforming numpy array to PIL Image
body: <p>I have a variable <code>img</code> which is a <code>int64 numpy.array</code> with sizes 28x28. Its content looks like this:</p>
  
  <pre><code>[...]
  [  0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
      0   0   0   0   0   0   0   0   0   0]
  [  0   0   0   0   0   0   0   0   0  68 154 188 176 254 254 254 254 254
    227 106  17   0   0   0   0   0   0   0]
  [...]
  </code></pre>
  
  <p>I want to convert the array to a PIL image. To do so I call <code>img = Image.fromarray(img, mode='L')</code> but the output I get is only 0s while it is obvious that it shouldn't be like that. I have checked the <code>mode</code> options and seems like L is correct. Also checked other answers inside stackoverflow and couldn't find something that reproduces this particular problem.</p>
  
  <blockquote>
    <p>L (8-bit pixels, black and white)</p>
  </blockquote>
  
  <p>Why is this "simple" piece of code given an unexpected behaviour? </p>
  
  <p>Thanks in advance!</p>