在OpenCV中获取像素值

Question

我是OpenCV的新手，我正试图从灰度图像中获取像素值。

#include<opencv2\opencv.hpp>
#include<opencv2\highgui\highgui.hpp>
#include<opencv2\core\core.hpp>
#include<iostream>

using namespace cv;

int main()
{
    VideoCapture cap(1);
    Mat image,gray_image;
    cap>>image;
    cvtColor(image,gray_image,CV_BGR2GRAY);
    std::cout<<"Value: "<<gray_image.at<uchar>(0,0);
    imshow("Window",gray_image);
    waitKey(0);
    return 0;
}

像素值显示为*或〜等。我认为它会转换为ASCII值。我该如何解决这个问题？

谢谢。

Answer 1

尝试输出为整数

std::cout<<"Value: "<<static_cast<int>(gray_image.at<uchar>(0,0));

Answer 2

您需要在打印前将uchar变量强制转换为int

等

std::cout<<"Value: "<<(int)src.at<uchar>(0,0);