Region of interest selection ROI

#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <string.h>
#include<opencv2\opencv.hpp>
#include <opencv2\highgui\highgui.hpp>


int main(int argc, char *argv[])
{
CvCapture *capture = 0;
IplImage *frame = 0;
int key = 0;
/* initialize camera */
capture = cvCaptureFromCAM( 0 );
/* always check */
if ( !capture ) {
printf("Cannot open initialize webcam!\n" );
exit(0);
}

/* create a window for the video */
cvNamedWindow( "result", CV_WINDOW_AUTOSIZE );
while( key != 'q' ) {
/* get a frame */
frame = cvQueryFrame( capture );

/* always check */
if( !frame ) break;
/* sets the Region of Interest*/
cvSetImageROI(frame, cvRect(150, 50, 150, 250));
/* create destination image */
IplImage *img2 = cvCreateImage(cvGetSize(frame),
frame->depth,
frame->nChannels);

/*
* do the main processing with subimage here.
* in this example, we simply invert the subimage
*/
cvNot(frame,frame);

/* copy subimage */
cvCopy(frame, img2, NULL);
/* always reset the Region of Interest */
cvResetImageROI(frame);

/* display current frame */
cvShowImage( "result", frame );
/* exit if user press 'q' */
key = cvWaitKey( 1 );
}

/* free memory */
cvDestroyWindow( "result" );
cvReleaseCapture( &capture );
return 0;
}