Kristou Says

This a source code for sircle detection.

void findCircles( IplImage* img, CvMemStorage* storage ){
CvSeq* circles;
IplImage* cpy = cvCreateImage(cvGetSize(img),8,1);
int i;
float* circ;
cvCvtColor(img,cpy,CV_RGB2GRAY);
circles =
cvHoughCircles(cpy,storage,CV_HOUGH_GRADIENT,2,cpy->height/4,200,100);
for(i=0;i < circles->total;i++){
CvSeq
circ=(float*)cvGetSeqElem(circles,i);

cvCircle(img,cvPoint(cvRound(circ[0]),cvRound(circ[1])),cvRound(circ[2]),CV_RGB(255,255,255),1,8,0);
}
cvReleaseImage(&cpy);

}