Kristou Says

This an example on how to use morphological operator in OpenCV to close gaps.

int main(int argc, char* argv[])

{

IplImage *image;

IplImage *dilated_image;

IplImage *eroded_image;

image = cvLoadImage ("triangle.jpg");
dilated_image = cvCloneImage (image);

eroded_image = cvCloneImage (image);
cvNamedWindow ("Original", 1);

cvNamedWindow ("Dilated", 1);

cvNamedWindow ("Eroded", 1);
cvShowImage ("Original", image);
cvDilate (image, dilated_image, 0, 7);

cvShowImage ("Dilated", dilated_image);
cvErode (dilated_image, eroded_image, 0, 6);

cvShowImage ("Eroded", eroded_image);
cvWaitKey ();
cvReleaseImage (&image);

cvDestroyWindow ("Original");

cvReleaseImage (&dilated_image);

cvDestroyWindow ("Dilated");

cvReleaseImage (&eroded_image);

cvDestroyWindow ("Eroded");
return 0;

}

						
 
					

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);

}