opencv 一张图片，鼠标左击时显示坐标并输出像素值，鼠标移动时不显示坐标

#include
#include
#include

using namespace cv;
using namespace std;

Mat src;
void on_mouse(int event, int x, int y, int flags, void* ustc);

int main(int argc, char* argv)
{
src = imread("D:/opencvproject/opencvPicture/chuizhitu.png");

namedWindow("input image", CV_WINDOW_AUTOSIZE);
setMouseCallback("input image", on_mouse, &src);

while (1)
{
imshow("input image", src);
waitKey(40);
}
return 0;
}

void on_mouse(int event, int x, int y, int flags, void* ustc)
{
if (event == CV_EVENT_LBUTTONDOWN)
{
Mat p;
p = *(Mat*)ustc;
Point pt = Point(x, y);
char temp[16];
sprintf_s(temp,"(%d,%d)", pt.x, pt.y);
putText(src, temp, pt, CV_FONT_HERSHEY_COMPLEX,0.5, Scalar(255, 0, 0),2,8);
printf("b=%d\t", p.at(pt)[0]);
printf("g=%d\t", p.at(pt)[1]);
printf("r=%d\n", p.at(pt)[2]);
circle(src, pt, 2, Scalar(0, 0, 255), 2, 8);
}

}

效果：