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