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本帖最后由 Ashimar 于 2018-3-31 14:59 编辑
本小白学到 opencv 的 cv2.matchTemplate() 函数,通过下面的代码能实现出效果,问题是当已知模板没有在图片内时,它也能匹配出一个区域来,想问是否有一个能判断匹配精确度的值,或者应该怎么区分是否匹配正确,求大神踩帖。
- import cv2
- import numpy as np
- from matplotlib import pyplot as plt
- img = cv2.imread('people.jpg',0)
- img2 = img.copy()
- template = cv2.imread('people_face.png',0)
- w, h = template.shape[::-1]
- # All the 6 methods for comparison in a list
- methods = ['cv2.TM_CCOEFF', 'cv2.TM_CCOEFF_NORMED', 'cv2.TM_CCORR',
- 'cv2.TM_CCORR_NORMED', 'cv2.TM_SQDIFF', 'cv2.TM_SQDIFF_NORMED']
- # 'cv2.TM_CCORR'
- for meth in methods:
- img = img2.copy()
- # exec 语句用来执行储存在字符串或文件中的 Python 语句。
- # 例如,我们可以在运行时生成一个包含 Python 代码的字符串,然后使用 exec 语句执行这些语句。
- # eval 语句用来计算存储在字符串中的有效 Python 表达式
- method = eval(meth) # Apply template Matching
- res = cv2.matchTemplate(img,template,method)
- min_val, max_val, min_loc, max_loc = cv2.minMaxLoc(res)
- # 使用不同的比较方法,对结果的解释不同
- # If the method is TM_SQDIFF or TM_SQDIFF_NORMED, take minimum
- if method in [cv2.TM_SQDIFF, cv2.TM_SQDIFF_NORMED]:
- top_left = min_loc
- else:
- top_left = max_loc
- bottom_right = (top_left[0] + w, top_left[1] + h)
- cv2.rectangle(img,top_left, bottom_right, 255, 2)
- print(top_left, bottom_right)
- # (220, 43) (312, 142)
- 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()
复制代码
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