轮廓3

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

#define w 500
int levels = 3;
CvSeq* contours = 0;

void on_trackbar(int pos)
{
IplImage* cnt_img = cvCreateImage( cvSize(w,w), 8, 3 );
CvSeq* _contours = contours;
int _levels = levels - 3;

// if( _levels <= 0 ) // get to the nearest face to make it look more funny
//   _contours = _contours->h_next->h_next->h_next->h_next->h_next;
cvZero( cnt_img );
cvDrawContours( cnt_img, _contours, CV_RGB(255,0,0), CV_RGB(0,255,0), _levels, 3, CV_AA, cvPoint(0,0) );
cvShowImage( "contours", cnt_img );
cvReleaseImage( &cnt_img );
}

int main( int argc, char** argv )
{
int i, j;
CvMemStorage* storage = cvCreateMemStorage(0);
IplImage* img = cvCreateImage( cvSize(w,w), 8, 1 );

cvZero( img );

for( i=0; i < 6; i++ )
{
int dx = (i%2)*250 - 30;
int dy = (i/2)*150;
CvScalar white = cvRealScalar(255);
CvScalar black = cvRealScalar(0);

if( i == 0 )
{

for( j = 0; j <= 10 ;j++ )
{
double angle = (j+5)*CV_PI/21;//弧度制中1度所对应的值
cvLine(img, cvPoint(cvRound(dx+100+j*10-80*cos(angle)),
cvRound(dy+100-90*sin(angle))),
cvPoint(cvRound(dx+100+j*10-30*cos(angle)),
cvRound(dy+100-30*sin(angle))), white, 1, 8, 0);
}
}

cvEllipse( img, cvPoint(dx+150, dy+100), cvSize(100,70), 0, 0, 360, white, -1, 8, 0 );
cvEllipse( img, cvPoint(dx+115, dy+70), cvSize(30,20), 0, 0, 360, black, -1, 8, 0 );
//    cvEllipse( img, cvPoint(dx+185, dy+70), cvSize(30,20), 0, 0, 360, black, -1, 8, 0 );
//  cvEllipse( img, cvPoint(dx+115, dy+70), cvSize(15,15), 0, 0, 360, white, -1, 8, 0 );
//   cvEllipse( img, cvPoint(dx+185, dy+70), cvSize(15,15), 0, 0, 360, white, -1, 8, 0 );
//   cvEllipse( img, cvPoint(dx+115, dy+70), cvSize(5,5), 0, 0, 360, black, -1, 8, 0 );
//   cvEllipse( img, cvPoint(dx+185, dy+70), cvSize(5,5), 0, 0, 360, black, -1, 8, 0 );
//    cvEllipse( img, cvPoint(dx+150, dy+100), cvSize(10,5), 0, 0, 360, black, -1, 8, 0 );
//    cvEllipse( img, cvPoint(dx+150, dy+150), cvSize(40,10), 0, 0, 360, black, -1, 8, 0 );
//    cvEllipse( img, cvPoint(dx+27, dy+100), cvSize(20,35), 0, 0, 360, white, -1, 8, 0 );
//     cvEllipse( img, cvPoint(dx+273, dy+100), cvSize(20,35), 0, 0, 360, white, -1, 8, 0 );
}

cvNamedWindow( "image", 1 );
cvShowImage( "image", img );

cvFindContours( img, storage, &contours, sizeof(CvContour),
CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, cvPoint(0,0) );

// comment this out if you do not want approximation
contours = cvApproxPoly( contours, sizeof(CvContour), storage, CV_POLY_APPROX_DP, 3, 1 );

cvNamedWindow( "contours", 1 );
cvCreateTrackbar( "levels+3", "contours", &levels, 7, on_trackbar );

on_trackbar(0);
cvWaitKey(0);
cvReleaseMemStorage( &storage );
cvReleaseImage( &img );

return 0;
}