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：

1. 对彩色图分离通道，拿到红色通道图
2. 进行阈值分割

#include<iostream>
#include<opencv2\opencv.hpp>
#include<opencv2\highgui\highgui.hpp>
#include<stdlib.h>
using namespace cv;
using namespace std;int main()
{char*  path = "D:\\01.jpg";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", binary);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(2, 2), Point(-1, -1));//dilate(red_binary, red_dilate, kernel);//Mat kernel = getStructuringElement(MORPH_ELLIPSE, Size(2, 2), Point(-1, -1));//morphologyEx(red_binary, red_dilate, MORPH_OPEN, kernel, Point(-1, -1));//imshow("red+binary+dilate", red_dilate);waitKey();return 0;
}