获取图片的某一坐标点的像素值

单通道图像

 

#include<iostream>
#include "opencv2/opencv.hpp"
#include "opencv2/highgui.hpp"
using namespace cv;
using namespace std;
uchar get_scale_value(Mat& input_img, int i, int j)
{
    uchar* p = input_img.ptr<uchar>(i);
    return p[j];
}
int main() {
    Mat src1 = imread("1.jpg");
    cout << (int)src1.at<uchar>(10, 10)<<endl;//154 
    //Gray = (R * 299 + G * 587 + B * 114 + 500) / 1000
    cout << (int)src1.at<Vec3b>(10, 10)[0]<<endl;//58
    cout << (int)src1.at<Vec3b>(10, 10)[1]<<endl;//169
    cout << (int)src1.at<Vec3b>(10, 10)[2]<<endl;//141
    Mat src2 = imread("1.jpg", 0);
    cout << (int)src2.at<uchar>(10, 10) << endl;//148
    cout << (int)get_scale_value(src2, 10, 10) << endl;//148
    cout << (int)get_scale_value(src1, 10, 10) << endl;//154
    return 0;
}