Template matching using OpenCV in Python

template_matching_opencv_python.py

import cv2
import numpy as np
img = cv2.imread("messi5.jpg")
grey_img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
template = cv2.imread("messi_face.jpg", 0)
w, h = template.shape[::-1]

res = cv2.matchTemplate(grey_img, template, cv2.TM_CCORR_NORMED )
print(res)
threshold = 0.99;
loc = np.where(res >= threshold)
print(loc)
for pt in zip(*loc[::-1]):
    cv2.rectangle(img, pt, (pt[0] + w, pt[1] + h), (0, 0, 255), 2)

cv2.imshow("img", img)
cv2.waitKey(0)
cv2.destroyAllWindows()

Getting error
w, h = template.shape[:-1]
AttributeError: 'NoneType' object has no attribute 'shape'

w, h = template.shape[::-1] # you should understand numpy indexing operation in a proper way

import cv2
import numpy as np

Load the main image

img = cv2.imread(r'C:\opencv-4.x\opencv-4.x\samples\data\lena.jpg')

Convert the main image to grayscale

grey_img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

Load the template image

template = cv2.imread(r'C:\opencv-4.x\opencv-4.x\samples\data\lena_face.jpg', 0)

Find the width and height of the template

w, h = template.shape[::-1]

Perform template matching

res = cv2.matchTemplate(grey_img, template, cv2.TM_CCORR_NORMED)

Set a threshold

threshold = 0.99

Find locations where the correlation coefficient is greater than the threshold

loc = np.where(res >= threshold)

Draw rectangles around the matched regions

for pt in zip(*loc[::-1]):
cv2.rectangle(img, pt, (pt[0] + w, pt[1] + h), (0, 0, 255), 2)

Display the result

cv2.imshow("img", img)
cv2.waitKey(0)
cv2.destroyAllWindows()

run this code