CODE EXAMPLE FOR PYTHON

waitkey in opencv

cv2.waitKey() 
# function store 'key' that you press during output windows open, 
# also wait for certain amount of time

#if yoy press 'q' then cv2.waitKey(1) replace with ASCII value which is 113
if cv2.waitKey(1000) & 0xFF == ord('q'): # wait for 1000 millisecond
  break

# now your code will look like this
if 113 & 0xFF == ord('q'):
  break