title: rectangle not showing up in opencv
body: <p>Why is rectangle not showing up in my code?</p>
  
  <pre><code>import cv2
  
  im = cv2.imread('players.bmp')
  
  #im.shape &gt;&gt;returns (765,1365,3)
  
  cv2.rectangle(im, (64,1248), (191,1311), (0,255,0), 2)
  cv2.namedWindow("image", cv2.WINDOW_NORMAL)
  cv2.imshow('image', im)
  cv2.waitKey(0)
  cv2.destroyAllWindows()
  </code></pre>