1. 实现方法

现实生活中，一些票据（比如发票、车票）等都会有一个红色印章，有时会盖在某个关键区域，影响了其他的字符识别。因此，为了提高准确率，我们尽量会移除红色印章，具体实现方法如下：

对彩色图分离通道，拿到红色通道图
进行阈值分割

2. 代码实现

int main()
{char* path = "C:\\Users\\Administrator\\Desktop\\piaoju.png";Mat src = imread(path);if (src.empty()) {return -1;}imshow("original", src);Mat gray;cvtColor(src, gray, CV_BGR2GRAY);//全局二值化int thresh_value = 100;Mat binary;threshold(gray, binary, thresh_value, 255, CV_THRESH_BINARY);imshow("binary", binary);vector<Mat> channes;split(src, channes);Mat red = channes[2];imshow("red", red);Mat red_binary;threshold(red, red_binary, thresh_value, 255, CV_THRESH_BINARY);imshow("red+binary", red_binary);Mat red_dilate;Mat kernel = getStructuringElement(MORPH_RECT, Size(3, 3), Point(-1, -1));dilate(red_binary, red_dilate, kernel);Mat kernel_ellipse = getStructuringElement(MORPH_ELLIPSE, Size(2, 2), Point(-1, -1));morphologyEx(red_binary, red_dilate, MORPH_OPEN, kernel_ellipse, Point(-1, -1));imshow("red+binary+dilate", red_dilate);waitKey();return 0;
}