git.maemo.org Git - opencv/blob - samples/c/lkdemo.c

   1 /* Demo of modified Lucas-Kanade optical flow algorithm.
   2    See the printf below */
   3
   4 #ifdef _CH_
   5 #pragma package <opencv>
   6 #endif
   7
   8 #ifndef _EiC
   9 #include "cv.h"
  10 #include "highgui.h"
  11 #include <stdio.h>
  12 #include <ctype.h>
  13 #endif
  14
  15 IplImage *image = 0, *grey = 0, *prev_grey = 0, *pyramid = 0, *prev_pyramid = 0, *swap_temp;
  16
  17 int win_size = 10;
  18 const int MAX_COUNT = 500;
  19 CvPoint2D32f* points[2] = {0,0}, *swap_points;
  20 char* status = 0;
  21 int count = 0;
  22 int need_to_init = 0;
  23 int night_mode = 0;
  24 int flags = 0;
  25 int add_remove_pt = 0;
  26 CvPoint pt;
  27
  28
  29 void on_mouse( int event, int x, int y, int flags, void* param )
  30 {
  31     if( !image )
  32         return;
  33
  34     if( image->origin )
  35         y = image->height - y;
  36
  37     if( event == CV_EVENT_LBUTTONDOWN )
  38     {
  39         pt = cvPoint(x,y);
  40         add_remove_pt = 1;
  41     }
  42 }
  43
  44
  45 int main( int argc, char** argv )
  46 {
  47     CvCapture* capture = 0;
  48
  49     if( argc == 1 || (argc == 2 && strlen(argv[1]) == 1 && isdigit(argv[1][0])))
  50         capture = cvCaptureFromCAM( argc == 2 ? argv[1][0] - '0' : 0 );
  51     else if( argc == 2 )
  52         capture = cvCaptureFromAVI( argv[1] );
  53
  54     if( !capture )
  55     {
  56         fprintf(stderr,"Could not initialize capturing...\n");
  57         return -1;
  58     }
  59
  60     /* print a welcome message, and the OpenCV version */
  61     printf ("Welcome to lkdemo, using OpenCV version %s (%d.%d.%d)\n",
  62             CV_VERSION,
  63             CV_MAJOR_VERSION, CV_MINOR_VERSION, CV_SUBMINOR_VERSION);
  64
  65     printf( "Hot keys: \n"
  66             "\tESC - quit the program\n"
  67             "\tr - auto-initialize tracking\n"
  68             "\tc - delete all the points\n"
  69             "\tn - switch the \"night\" mode on/off\n"
  70             "To add/remove a feature point click it\n" );
  71
  72     cvNamedWindow( "LkDemo", 0 );
  73     cvSetMouseCallback( "LkDemo", on_mouse, 0 );
  74
  75     for(;;)
  76     {
  77         IplImage* frame = 0;
  78         int i, k, c;
  79
  80         frame = cvQueryFrame( capture );
  81         if( !frame )
  82             break;
  83
  84         if( !image )
  85         {
  86             /* allocate all the buffers */
  87             image = cvCreateImage( cvGetSize(frame), 8, 3 );
  88             image->origin = frame->origin;
  89             grey = cvCreateImage( cvGetSize(frame), 8, 1 );
  90             prev_grey = cvCreateImage( cvGetSize(frame), 8, 1 );
  91             pyramid = cvCreateImage( cvGetSize(frame), 8, 1 );
  92             prev_pyramid = cvCreateImage( cvGetSize(frame), 8, 1 );
  93             points[0] = (CvPoint2D32f*)cvAlloc(MAX_COUNT*sizeof(points[0][0]));
  94             points[1] = (CvPoint2D32f*)cvAlloc(MAX_COUNT*sizeof(points[0][0]));
  95             status = (char*)cvAlloc(MAX_COUNT);
  96             flags = 0;
  97         }
  98
  99         cvCopy( frame, image, 0 );
 100         cvCvtColor( image, grey, CV_BGR2GRAY );
 101
 102         if( night_mode )
 103             cvZero( image );
 104
 105         if( need_to_init )
 106         {
 107             /* automatic initialization */
 108             IplImage* eig = cvCreateImage( cvGetSize(grey), 32, 1 );
 109             IplImage* temp = cvCreateImage( cvGetSize(grey), 32, 1 );
 110             double quality = 0.01;
 111             double min_distance = 10;
 112
 113             count = MAX_COUNT;
 114             cvGoodFeaturesToTrack( grey, eig, temp, points[1], &count,
 115                                    quality, min_distance, 0, 3, 0, 0.04 );
 116             cvFindCornerSubPix( grey, points[1], count,
 117                 cvSize(win_size,win_size), cvSize(-1,-1),
 118                 cvTermCriteria(CV_TERMCRIT_ITER|CV_TERMCRIT_EPS,20,0.03));
 119             cvReleaseImage( &eig );
 120             cvReleaseImage( &temp );
 121
 122             add_remove_pt = 0;
 123         }
 124         else if( count > 0 )
 125         {
 126             cvCalcOpticalFlowPyrLK( prev_grey, grey, prev_pyramid, pyramid,
 127                 points[0], points[1], count, cvSize(win_size,win_size), 3, status, 0,
 128                 cvTermCriteria(CV_TERMCRIT_ITER|CV_TERMCRIT_EPS,20,0.03), flags );
 129             flags |= CV_LKFLOW_PYR_A_READY;
 130             for( i = k = 0; i < count; i++ )
 131             {
 132                 if( add_remove_pt )
 133                 {
 134                     double dx = pt.x - points[1][i].x;
 135                     double dy = pt.y - points[1][i].y;
 136
 137                     if( dx*dx + dy*dy <= 25 )
 138                     {
 139                         add_remove_pt = 0;
 140                         continue;
 141                     }
 142                 }
 143
 144                 if( !status[i] )
 145                     continue;
 146
 147                 points[1][k++] = points[1][i];
 148                 cvCircle( image, cvPointFrom32f(points[1][i]), 3, CV_RGB(0,255,0), -1, 8,0);
 149             }
 150             count = k;
 151         }
 152
 153         if( add_remove_pt && count < MAX_COUNT )
 154         {
 155             points[1][count++] = cvPointTo32f(pt);
 156             cvFindCornerSubPix( grey, points[1] + count - 1, 1,
 157                 cvSize(win_size,win_size), cvSize(-1,-1),
 158                 cvTermCriteria(CV_TERMCRIT_ITER|CV_TERMCRIT_EPS,20,0.03));
 159             add_remove_pt = 0;
 160         }
 161
 162         CV_SWAP( prev_grey, grey, swap_temp );
 163         CV_SWAP( prev_pyramid, pyramid, swap_temp );
 164         CV_SWAP( points[0], points[1], swap_points );
 165         need_to_init = 0;
 166         cvShowImage( "LkDemo", image );
 167
 168         c = cvWaitKey(10);
 169         if( (char)c == 27 )
 170             break;
 171         switch( (char) c )
 172         {
 173         case 'r':
 174             need_to_init = 1;
 175             break;
 176         case 'c':
 177             count = 0;
 178             break;
 179         case 'n':
 180             night_mode ^= 1;
 181             break;
 182         default:
 183             ;
 184         }
 185     }
 186
 187     cvReleaseCapture( &capture );
 188     cvDestroyWindow("LkDemo");
 189
 190     return 0;
 191 }
 192
 193 #ifdef _EiC
 194 main(1,"lkdemo.c");
 195 #endif