How can I find objects in a game screenshot?

Question

Python

I want to recognize objects in screenshots that will be received via adb where the ClashOfClans game will be launched.
I tried to find the Town Hall using OpenCV but with mixed success. On some screenshots it worked, on some it didn't.
Here is the pattern to look for:

the code

import cv2 as cv
import numpy
from matplotlib import  pyplot as plt
img = cv.imread('screen_4.jpg',0)
img2 = img.copy()

template = cv.imread('temp_2.bmp',0)
w, h  = template.shape[::-1]


methods = ['cv.TM_CCOEFF', 'cv.TM_CCOEFF_NORMED', 'cv.TM_CCORR',
        'cv.TM_CCORR_NORMED', 'cv.TM_SQDIFF', 'cv.TM_SQDIFF_NORMED']

for meth in methods:
    img = img2.copy()
    method = eval(meth)

    rev = cv.matchTemplate(img, template, method)
    min_val, max_val, min_loc, max_loc = cv.minMaxLoc(rev)

    if method in [cv.TM_SQDIFF, cv.TM_SQDIFF_NORMED]:
        top_left = min_loc
    else:
        top_left = max_loc

    bottom_right = (top_left[0] + w, top_left[1] + h)

    cv.rectangle(img, top_left, bottom_right, 255, 2)

    print(top_left, bottom_right)

    plt.subplot(121), plt.imshow(rev, cmap='gray')
    plt.title('Matching Result'), plt.xticks([]), plt.yticks([])
    plt.subplot(122), plt.imshow(img, cmap='gray')
    plt.title('Detected Point'), plt.xticks([]), plt.yticks([])
    plt.suptitle(meth)
    plt.show()

Что делать? Есть ли 100% варианты распознавания объектов по шаблону?

Answer 1

the result was mixed success

due to the enumeration of comparison methods:

methods = ['cv.TM_CCOEFF', 'cv.TM_CCOEFF_NORMED', 'cv.TM_CCORR',
        'cv.TM_CCORR_NORMED', 'cv.TM_SQDIFF', 'cv.TM_SQDIFF_NORMED']

for meth in methods:
    img = img2.copy()
    method = eval(meth)

It is necessary to leave one most effective method.