我想搜索使用matplotlib绘制的图形图像，我将图像保存如下。我只想搜索绘制在pdf图片顶部的线条，如下图所示。我已经使用cv2.matchTemplate（）相同。但是它显示出一些不匹配的区域。

    img = cv2.imread(source_image,0)
    img2 = img.copy()
    template = cv2.imread(target_image,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']

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

        # Apply template Matching
        res = cv2.matchTemplate(img,template,method)
        min_val,max_val,min_loc,max_loc = cv2.minmaxLoc(res)
        print (min_val)
        print (max_val)
        print (min_loc)
        print (max_loc)
        # 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,(0,255),2)
        #cv2.imwrite('res{}.png'.format(meth),img)
        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.yticks([])
        plt.suptitle(meth)
        plt.show()

我已经调整了图像的大小，并尝试按细分进行搜索，但仍然无法实现。输出显示为模板匹配，但在错误的地方显示矩形。请提出建议。