OpenCV: contours.c

00001 #ifdef _CH_
00002 #pragma package <opencv>
00003 #endif
00004 
00005 #ifndef _EiC
00006 #include "cv.h"
00007 #include "highgui.h"
00008 #include <math.h>
00009 #endif
00010 
00011 #define w 500
00012 int levels = 3;
00013 CvSeq* contours = 0;
00014 
00015 void on_trackbar(int pos)
00016 {
00017     IplImage* cnt_img = cvCreateImage( cvSize(w,w), 8, 3 );
00018     CvSeq* _contours = contours;
00019     int _levels = levels - 3;
00020     if( _levels <= 0 ) // get to the nearest face to make it look more funny
00021         _contours = _contours->h_next->h_next->h_next;
00022     cvZero( cnt_img );
00023     cvDrawContours( cnt_img, _contours, CV_RGB(255,0,0), CV_RGB(0,255,0), _levels, 3, CV_AA, cvPoint(0,0) );
00024     cvShowImage( "contours", cnt_img );
00025     cvReleaseImage( &cnt_img );
00026 }
00027 
00028 int main( int argc, char** argv )
00029 {
00030     int i, j;
00031     CvMemStorage* storage = cvCreateMemStorage(0);
00032     IplImage* img = cvCreateImage( cvSize(w,w), 8, 1 );
00033 
00034     cvZero( img );
00035 
00036     for( i=0; i < 6; i++ )
00037     {
00038         int dx = (i%2)*250 - 30;
00039         int dy = (i/2)*150;
00040         CvScalar white = cvRealScalar(255);
00041         CvScalar black = cvRealScalar(0);
00042 
00043         if( i == 0 )
00044         {
00045             for( j = 0; j <= 10; j++ )
00046             {
00047                 double angle = (j+5)*CV_PI/21;
00048                 cvLine(img, cvPoint(cvRound(dx+100+j*10-80*cos(angle)),
00049                     cvRound(dy+100-90*sin(angle))),
00050                     cvPoint(cvRound(dx+100+j*10-30*cos(angle)),
00051                     cvRound(dy+100-30*sin(angle))), white, 1, 8, 0);
00052             }
00053         }
00054 
00055         cvEllipse( img, cvPoint(dx+150, dy+100), cvSize(100,70), 0, 0, 360, white, -1, 8, 0 );
00056         cvEllipse( img, cvPoint(dx+115, dy+70), cvSize(30,20), 0, 0, 360, black, -1, 8, 0 );
00057         cvEllipse( img, cvPoint(dx+185, dy+70), cvSize(30,20), 0, 0, 360, black, -1, 8, 0 );
00058         cvEllipse( img, cvPoint(dx+115, dy+70), cvSize(15,15), 0, 0, 360, white, -1, 8, 0 );
00059         cvEllipse( img, cvPoint(dx+185, dy+70), cvSize(15,15), 0, 0, 360, white, -1, 8, 0 );
00060         cvEllipse( img, cvPoint(dx+115, dy+70), cvSize(5,5), 0, 0, 360, black, -1, 8, 0 );
00061         cvEllipse( img, cvPoint(dx+185, dy+70), cvSize(5,5), 0, 0, 360, black, -1, 8, 0 );
00062         cvEllipse( img, cvPoint(dx+150, dy+100), cvSize(10,5), 0, 0, 360, black, -1, 8, 0 );
00063         cvEllipse( img, cvPoint(dx+150, dy+150), cvSize(40,10), 0, 0, 360, black, -1, 8, 0 );
00064         cvEllipse( img, cvPoint(dx+27, dy+100), cvSize(20,35), 0, 0, 360, white, -1, 8, 0 );
00065         cvEllipse( img, cvPoint(dx+273, dy+100), cvSize(20,35), 0, 0, 360, white, -1, 8, 0 );
00066     }
00067 
00068     cvNamedWindow( "image", 1 );
00069     cvShowImage( "image", img );
00070 
00071     cvFindContours( img, storage, &contours, sizeof(CvContour),
00072                     CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, cvPoint(0,0) );
00073 
00074     // comment this out if you do not want approximation
00075     contours = cvApproxPoly( contours, sizeof(CvContour), storage, CV_POLY_APPROX_DP, 3, 1 );
00076 
00077     cvNamedWindow( "contours", 1 );
00078     cvCreateTrackbar( "levels+3", "contours", &levels, 7, on_trackbar );
00079     
00080     on_trackbar(0);
00081     cvWaitKey(0);
00082     cvReleaseMemStorage( &storage );
00083     cvReleaseImage( &img );
00084 
00085     return 0;
00086 }
00087 
00088 #ifdef _EiC
00089 main(1,"");
00090 #endif