title: Expanded GUI for openCV with python and conda
body: <p>I'm using <strong>opencv 3.3</strong> with <strong>python3.6.3</strong> that I installed in a <strong>conda</strong> environment and for a while, when displaying images (with the basic cv2 function <code>imshow("window name", my_image)</code> for example) a small GUI would be displayed with the image. I was also able to zoom in and out at will and even go as far as being able to see the RGB intensities of each of the image's pixels. </p>
  
  <p>That was pretty handy, but I recently updated my opencv version with conda (<code>3.3.0 -&gt; 3.3.1</code>) and the feature is gone. Downgrading the cv2 module doesn't bring the feature back.</p>
  
  <p>I've gathered, from what I've found, that one can manually enable this feature by adding the flag <code>cv2.WINDOW_GUI_EXPANDED</code> whilst creating the window but it does not change anything on the displayed window.</p>
  
  <p>I managed to print all the available flags in cv2 (with <code>&gt;&gt;help(cv2)</code> on python) and that particular flag doesn't seem to be set :</p>
  
  <p><a href="https://i.stack.imgur.com/X34nx.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/X34nx.png" alt="Python cv2 help screenshot"></a></p>
  
  <p>Apparently, one should build opencv with Qt in order to gain access to that flag, but is that possible with conda? </p>
  
  <p>While looking at the opencv Documentation you can see that they feature both <code>EXPANDED</code> (below) and <code>NORMAL</code> (above) GUI</p>
  
  <p><a href="https://i.stack.imgur.com/h0YWb.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/h0YWb.png" alt="OpenCV documentation"></a></p>
  
  <p>How could I set this flag to work with my current opencv version? Or do I need to build my cv2 module with Qt on conda? And if yes, how so?</p>