opencv鼠标取样+灰度简单二值化

 鼠标右键取样，作为灰度分界线进行最简单的二值化处理

效果图：

#include<opencv2/opencv.hpp>
#include<iostream>

using namespace cv;
using namespace std;
bool flag = false;
Mat image;
int val1, val2, val3;

void mouse_call_back(int event, int x, int y, int flags, void *userdata);

int main(int argc, char *argv[]) {
    namedWindow("img", 0);
    image = imread("/home/rubo/1.jpg");
    if (image.empty()) {
        cout << "no picture!" << endl;
        return 0;
    }
    cvtColor(image, image, COLOR_RGB2GRAY, 0);
    // inRange(image, Scalar(0), Scalar(100), image);
    imshow("img", image);
    setMouseCallback("img", mouse_call_back, 0);
    waitKey(0);
    return 0;
}

void mouse_call_back(int event, int x, int y, int flags, void *userdata) {
    switch (event) {
        case EVENT_RBUTTONDOWN: {
            flag = 1;
            break;
        }
        case EVENT_RBUTTONUP: {
            if (flag) {
                val1 = image.at<Vec3b>(y, x)[0];
                //   val2 =image.at<Vec3b>(y, x)[1];
                //   val3 = image.at<Vec3b>(y, x)[2];
                cout << val1 << endl;
                Mat result;
                inRange(image, Scalar(0), Scalar(val1), result);
                namedWindow("result", 0);
                imshow("result", result);
            }
            flag = 0;
            break;
        }
    }
}