（11）模板匹配

1.可以找出与小图片匹配的位置

import cv2                                                                                                                           
import numpy as np

img_bgr=cv2.imread('opencv-template-matching-python-tutorial.jpg')
img_gray = cv2.cvtColor(img_bgr,cv2.COLOR_BGR2GRAY)

template = cv2.imread('opencv-template-for-matching.jpg',0)
w,h = template.shape[::-1]
res = cv2.matchTemplate(img_gray,template,cv2.TM_CCOEFF_NORMED)
threshold=0.8
loc=np.where(res>= threshold)
#mask all these
for pt in zip(*loc[::-1]):
   cv2.rectangle(img_bgr,pt,(pt[0]+w,pt[1]+h),(0,255,255,2))
cv2.imshow('detected',img_bgr)
cv2.waitKey(0)
cv2.destroyAllWindows()