title: OpenCV subplots images with titles and space around borders
body: <p>I am looking to display some images in <strong>OpenCV Python</strong> with titles and borders around the each subplot. something like this (courtesy of the following stackoverflow post: <a href="https://stackoverflow.com/questions/37669622/opencv-python-video-subplots">OpenCV (Python) video subplots</a>):</p>
  
  <p><strong>WHAT I WANT:</strong>
  <a href="https://i.stack.imgur.com/UE4m7.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/UE4m7.jpg" alt="enter image description here"></a></p>
  
  <p>But I only manage to get this with that code adapted.</p>
  
  <pre><code> import cv2
   im1 = cv2.imread('Lenna.png')
   final_frame = cv2.hconcat((im1, im1))
   cv2.imshow('lena', final_frame)
  </code></pre>
  
  <p><s> <strong>WHAT I HAVE</strong>
  <a href="https://i.stack.imgur.com/SqWMq.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SqWMq.jpg" alt="enter image description here"></a> </s></p>
  
  <p>Is it possible to obtain this using OpenCV?
   I know a workaround would be to put text on the images, but that's not what I want because it will cover important information that way.</p>
  
  <p><strong>UPDATE</strong></p>
  
  <p>My bad, I didn't specify initially: <strong>I have 4 subplots</strong> (so 4 different images) and not two like in the example. Also, I want the solution to be as fast as possible since I have video (time restrictions)</p>
  
  <p><a href="https://i.stack.imgur.com/dLUjY.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/dLUjY.jpg" alt="enter image description here"></a></p>