Python opencvでカメラを開く

import cv2
import numpy as np #   
cap = cv2.VideoCapture(0) #      0                    ，    1,2,3....
while True:   #      
	ret,frame = cap.read() #           frame 
	cv2.imshow('frame',frame) # frame                     ，    
	c = cv2.waitKey(1) #           'Q'     ，   
	if c == ord('q'):
		break
cap.release()  #    
cv2.DestroyAllWindows()

開く効果