[OpenCV]: find circle with Hough transform

#include <cv.h>
#include <highgui.h>
#include <math.h>

int main(int argc, char** argv) {
  IplImage* image = cvLoadImage( 
    "circle.jpg",
    CV_LOAD_IMAGE_GRAYSCALE
  );
 IplImage* src = cvLoadImage("circle.jpg");
 CvMemStorage* storage = cvCreateMemStorage(0);
 cvSmooth(image, image, CV_GAUSSIAN, 5, 5 );
 CvSeq* results = cvHoughCircles( 
    image, 
    storage, 
    CV_HOUGH_GRADIENT, 
    4, 
    image->width/10 
  ); 

 for( int i = 0; i < results->total; i++ ) 
 {
    float* p = (float*) cvGetSeqElem( results, i );
    CvPoint pt = cvPoint( cvRound( p[0] ), cvRound( p[1] ) );
    cvCircle( 
      src,
      pt, 
      cvRound( p[2] ),
      CV_RGB(0xff,0,0) 
    );
  }
  cvNamedWindow( "HoughCircles", 1 );
  cvShowImage( "HoughCircles", src);
  cvWaitKey(0);
}

codes from 'learning opencv' book examples