Example script for object detection with opencv template matching

cv2_template_matching.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# http://docs.opencv.org/trunk/df/dfb/group__imgproc__object.html#ga586ebfb0a7fb604b35a23d85391329be
from __future__ import print_function
import argparse
import sys
try:
    import cv2
except ImportError:
    print("Install opencv python binding first", file=sys.stderr)
    sys.exit(1)

def main(src_path, tepl_path, method=cv2.TM_CCORR_NORMED):
    """
    Main function for object detection with template matching
    """
    img = cv2.imread(src_path, cv2.IMREAD_COLOR)
    template = cv2.imread(tepl_path, cv2.IMREAD_COLOR)

    resp = cv2.matchTemplate(img, template, method)
    _, _, min_loc, max_loc = cv2.minMaxLoc(resp)
    if method in [cv2.TM_SQDIFF, cv2.TM_SQDIFF_NORMED]:
        ori = min_loc
    else:
        ori = max_loc
    print("ori: {}".format(ori))
    tepl_h, tepl_w = template.shape[:2]
    buttom_right = (ori[0]+tepl_w, ori[1]+tepl_h)
    cv2.rectangle(img, ori, buttom_right, (0, 0, 255), 2)
    cv2.imwrite("result.png", img)

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="object detecting with template matching")
    parser.add_argument("src_path", metavar="SRC_PATH", help="source image path")
    parser.add_argument("tepl_path", metavar="TEPL_PATH", help="template image path")
    args = vars(parser.parse_args())
    main(**args)

source image

template

result: