title: Heatmap on top of image
body: <p>I have Images of different objects (Pascal Voc) and I have a probability heatmap. I want to visualize it by plotting the image and somehow the heatmap on top of it. What would be the best way to do that?</p>
  
  <p>I was thinking about using the alpha channel like this:</p>
  
  <pre><code>im_heat = np.zeros((image.shape[0],image.shape[1],4))
  im_heat[:,:,:3] = image
  im_heat[:,:,3] = np.rint(255/heatmap)
  plt.imshow(im_heat, cmap='jet')
  plt.colorbar()
  </code></pre>
  
  <p>How do I customize the colorbar to be from min(heatmap) to max(heatmap)?
  Or is there any better way to visualize the probabilities?</p>