title: How to show numpy 2d array as grayscale image in Jupyter Notebook?
body: <p>I have numpy array with the following properties.</p>
  
  <pre><code>np.shape(I)
  (300, 300)
  
  np.min(I)
  115
  
  np.max(I)
  250
  </code></pre>
  
  <p>Unfortunately, when I plot it, I get something greenish bluish.</p>
  
  <p>How to get normal grayscale palette?</p>
  
  <p><a href="https://i.stack.imgur.com/nUWRC.png" rel="noreferrer"><img src="https://i.stack.imgur.com/nUWRC.png" alt="enter image description here"></a></p>