使用 Open CV Python 在图像中查找模板/对象

Question

I'm working on project related to medical tests, in which I need to find out if test is positive, negative or invalid. below is example of my project needs

1. input image

2. check for test result like in below image

I have tried template detection example using OpenCV but its not accurate.

below is code which i tried

import cv2 as cv
import numpy as np
from matplotlib import pyplot as plt
img = cv.imread('s4.jpg', 0)
img2 = img.copy()
template = cv.imread('sub-2.jpeg', 0)
w, h = template.shape[::-1]
# All the 6 methods for comparison in a list
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)
    # Apply template Matching
    res = cv.matchTemplate(img, template, method)
    min_val, max_val, min_loc, max_loc = cv.minMaxLoc(res)
    # If the method is TM_SQDIFF or TM_SQDIFF_NORMED, take minimum
    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)
    plt.subplot(121), plt.imshow(res, 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()

Answer 1

感谢大家的建议，我可以使用边缘检测来解决这个问题，找出测试结果框，然后检测到没有水平线来获得结果。