学步园

#include "stdafx.h"
#include <iostream>
#include <cv.h>
#include <highgui.h>

using namespace cv;
using namespace std;

Rect box;
bool drawing_box = false;
bool gotBB = false;
int *initialBB;

void mouseHandler(int event, int x, int y, int flags, void *param){
  switch( event ){
  case CV_EVENT_MOUSEMOVE:
    if (drawing_box){
        box.width = x-box.x;
        box.height = y-box.y;
    }
    break;
  case CV_EVENT_LBUTTONDOWN:
    drawing_box = true;
    box = Rect( x, y, 0, 0 );
    break;
  case CV_EVENT_LBUTTONUP:
    drawing_box = false;
    if( box.width < 0 ){
        box.x += box.width;
        box.width *= -1;
    }
    if( box.height < 0 ){
        box.y += box.height;
        box.height *= -1;
    }
    gotBB = true;
    break;
  }
}
void drawBox(Mat& image, CvRect box, Scalar color, int thick){
  rectangle( image, cvPoint(box.x, box.y), cvPoint(box.x+box.width,box.y+box.height),color, thick);
} 



int _tmain(int argc, _TCHAR* argv[])
{   
	char windowName[1024] = "result";
	namedWindow(windowName,CV_WINDOW_AUTOSIZE);
	VideoCapture capture;
	capture.open(0);
	capture.set(CV_CAP_PROP_FRAME_WIDTH,320);
        capture.set(CV_CAP_PROP_FRAME_HEIGHT,240);
	Mat frame;
	cvSetMouseCallback( windowName, mouseHandler, NULL );
	GETBOUNDINGBOX:
	  while(!gotBB)
	  {
		capture>>frame;
		drawBox(frame,box,Scalar(255,0,0),2);
		imshow(windowName, frame);
		if (cvWaitKey(33) == 27)
			return 0;
	  }
	  if (min(box.width,box.height)<20){
		  cout << "Bounding box too small, try again." << endl;
		  gotBB = false;
		  goto GETBOUNDINGBOX;
	  }
	  cvSetMouseCallback( windowName, NULL, NULL );

	 return 0;
}