opencv(10)模糊匹配

模糊匹配 是一种用于较大图像中搜索和查找模板图像位置的方法

import cv2 as cv
import numpy as np
from matplotlib import pyplot as plot
# 单匹配方式
def mathTemplate():
    # 读取图片
    img = cv.imread("images/tg.jpg", 0)
    # 复制图片
    img2 = img.copy()
    template = cv.imread("images/mb.png", 0)
    width, height = template.shape[:2]
    # 列表中所有的6种比较方法
    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)
        # 应用模板匹配
        res = cv.matchTemplate(img, template, method)
        # minMaxLoc寻找矩阵中最大和最小的位置
        min_val, max_val, min_loc, max_loc = cv.minMaxLoc(res)
        if method in [cv.TM_SQDIFF, cv.TM_SQDIFF_NORMED]:
            top_left = max_loc
        else:
            top_left = max_loc
        bottom_right = (top_left[0] + width, top_left[1] + height)
        # 在图片上面绘制矩形边框
        cv.rectangle(img, top_left, bottom_right, 255, 3)
        plot.xticks([]), plot.yticks([])
        plot.subplot(122), plot.imshow(img, cmap='gray')
        plot.xticks([]), plot.yticks([])
        plot.suptitle(meth)
        plot.show()
# 多匹配方式
def matchMore():
    # 读取图片
    img_rgb = cv.imread('mario.png')
    # 转换颜色为灰色
    img_gray = cv.cvtColor(img_rgb, cv.COLOR_BGR2GRAY)
    template = cv.imread('mario_coin.png', 0)
    # 获取款跟高
    w, h = template.shape[::-1]
    # 匹配模板 采用TM_CCOEFF_NORMED
    res = cv.matchTemplate(img_gray, template, cv.TM_CCOEFF_NORMED)
    threshold = 0.8
    loc = np.where(res >= threshold)
    for pt in zip(*loc[::-1]):
        # 绘画方框
        cv.rectangle(img_rgb, pt, (pt[0] + w, pt[1] + h), (0, 0, 255), 2)
    cv.imwrite('res.png', img_rgb)
if __name__ == '__main__':
    mathTemplate()