opencv3+python3轮廓检测

import cv2 
  
img = cv2.imread('1.jpg') 
gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY) 
ret, binary = cv2.threshold(gray,127,255,cv2.THRESH_BINARY) 
  
image,cnts,hierarchy=cv2.findContours(binary,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE) 
cv2.drawContours(img,cnts,-1,(0,0,255),3) 
  
cv2.imshow("img", img) 

cv2.waitKey(0)