OpenCV学习笔记——点击显示鼠标坐标

点击显示鼠标显示坐标，再次点击时上一次的坐标的会消失……

#include<highgui.h>
#include<cv.h>
void on_mouse(int event, int x, int y, int flags, void* img)
{
	CvFont font;
	cvInitFont(&font, CV_FONT_HERSHEY_SIMPLEX, 0.5, 0.5, 0, 1, CV_AA);
	if (event == CV_EVENT_LBUTTONDOWN)
	{
		IplImage *timg = cvCloneImage((IplImage *)img);
		CvPoint pt = cvPoint(x, y);
		char temp[16];
		sprintf(temp, "(%d,%d)", x, y);
		cvPutText(timg, temp, pt, &font, CV_RGB(250,0,0));
		cvCircle(timg, pt, 2, cvScalar(255, 0, 0, 0), CV_FILLED, CV_AA, 0);
		cvShowImage("src", timg);
		cvReleaseImage(&timg);
	}
}

int main()
{
	IplImage *img = cvLoadImage("timg.jpg", 1);
	cvNamedWindow("src", 1);
	cvSetMouseCallback("src", on_mouse,img);
	cvShowImage("src", img);
	cvWaitKey(0);
	cvDestroyAllWindows();
	cvReleaseImage(&img);
	return 0;
}