title: How to get cv2.imshow() to show frames from a list?
body: <p>I am trying to save the last 50 frames from my webcam into a list and then play those frames back.  When I try to display the frame the display window shows gray and says it is unresponsive.  If I show the frame in the while loop it displays but if i try to show the frames from the list i saved them in the above issue occurs.  This is the code I am running.</p>
  
  <pre><code>cap = cv2.VideoCapture(0)
  image_list = []
  count = 0
  while(True):
      # Capture frame-by-frame
      ret, frame = cap.read()
  
      image_list.append(frame)
  
      #Display the resulting frame
      #cv2.imshow('frame',frame)   &lt;---  this will show me my live frame by frame capture
  
      if count &gt;= 50:
          break
  
      count += 1
  
  # When everything is done, release the capture
  cap.release()
  
  for image in image_list:  
      cv2.imshow("frame", image)
      sleep(1)
  </code></pre>