轉：基於Opencv的MeanShift跟蹤演算法實現

 

基於Opencv的MeanShift跟蹤演算法實現

#include "cv.h"
#include "highgui.h"
#include <stdio.h>
#include <ctype.h>

IplImage *image = 0, *hsv = 0, *hue = 0, *mask = 0, *backproject = 0, *histimg = 0;//用HSV中的Hue分量進行跟蹤
CvHistogram *hist = 0;//長條圖類

int backproject_mode = 0;
int select_object = 0;
int track_object = 0;
int show_hist = 1;
CvPoint origin;
CvRect selection;
CvRect track_window;
CvBox2D track_box; // Meanshift跟蹤演算法返回的Box類
CvConnectedComp track_comp;
int hdims = 50; // 劃分長條圖bins的個數，越多越精確

float hranges_arr[] = {0,180};//像素值的範圍
float* hranges = hranges_arr;//用於初始化CvHistogram類
int vmin = 10, vmax = 256, smin = 30;

void on_mouse( int event, int x, int y, int flags,void *NotUsed)//該函數用於選擇跟蹤目標
{
      if( !image )
         return;

     if( image->origin )
         y = image->height - y;

     if( select_object )//如果處於選擇跟蹤物體階段，則對selection用當前的滑鼠位置進行設定
     {
         selection.x = MIN(x,origin.x);
         selection.y = MIN(y,origin.y);
         selection.width = selection.x + CV_IABS(x - origin.x);
         selection.height = selection.y + CV_IABS(y - origin.y);

         selection.x = MAX( selection.x, 0 );
         selection.y = MAX( selection.y, 0 );
         selection.width = MIN( selection.width, image->width );
         selection.height = MIN( selection.height, image->height );
         selection.width -= selection.x;
         selection.height -= selection.y;

      }

      switch( event )
      {
            case CV_EVENT_LBUTTONDOWN://開始點擊選擇跟蹤物體
                   origin = cvPoint(x,y);
                   selection = cvRect(x,y,0,0);//座標
                   select_object = 1;//表明開始進行選取
            break;
           case CV_EVENT_LBUTTONUP:
                   select_object = 0;//選取完成
                   if( selection.width > 0 && selection.height > 0 )
                       track_object = -1;//如果選擇物體有效，則開啟跟蹤功能

           break;
      }
}

CvScalar hsv2rgb( float hue )//用於將Hue量轉換成RGB量
{
    int rgb[3], p, sector;
    static const int sector_data[][3]={{0,2,1}, {1,2,0}, {1,0,2}, {2,0,1}, {2,1,0}, {0,1,2}};
    hue *= 0.033333333333333333333333333333333f;
    sector = cvFloor(hue);
    p = cvRound(255*(hue - sector));
    p ^= sector & 1 ? 255 : 0;

    rgb[sector_data[sector][0]] = 255;
    rgb[sector_data[sector][1]] = 0;
    rgb[sector_data[sector][2]] = p;

    return cvScalar(rgb[2], rgb[1], rgb[0],0);//返回對應的顏色值
}

int main( int argc, char** argv )
{
    CvCapture* capture = 0;
    IplImage* frame = 0;

    if( argc == 1 || (argc == 2 && strlen(argv[1]) == 1 && isdigit(argv[1][0])))
         capture = cvCaptureFromCAM( argc == 2 ? argv[1][0] - '0' : 0 );//開啟網路攝影機
    else if( argc == 2 )
         capture = cvCaptureFromAVI( argv[1] );//開啟AVI檔案

    if( !capture )
    {
        fprintf(stderr,"Could not initialize capturing.../n");//開啟視頻流失敗處理
        return -1;
     }

    printf( "Hot keys: /n/tESC - quit the program/n/tc - stop the tracking/n/tb - switch to/from backprojection view/n/th - show/hide object histogram/nTo initialize tracking, select the object with mouse/n" );//列印出程式功能列表
    cvNamedWindow( "CamShiftDemo", 1 );//建立視頻視窗
    cvSetMouseCallback( "CamShiftDemo", on_mouse ); // 設定滑鼠回呼函數

    cvCreateTrackbar( "Vmin", "CamShiftDemo", &vmin, 256, 0 );//建立滑動條
    cvCreateTrackbar( "Vmax", "CamShiftDemo", &vmax, 256, 0 );
    cvCreateTrackbar( "Smin", "CamShiftDemo", &smin, 256, 0 );

    for(;;)//進入視訊框架處理主迴圈
   {
       int i, bin_w, c;
       frame = cvQueryFrame( capture );
       if( !frame )
               break;

      if( !image )//剛開始先建立一些緩衝區
      {

          image = cvCreateImage( cvGetSize(frame), 8, 3 );//
          image->origin = frame->origin;
          hsv = cvCreateImage( cvGetSize(frame), 8, 3 );
          hue = cvCreateImage( cvGetSize(frame), 8, 1 );
          mask = cvCreateImage( cvGetSize(frame), 8, 1 );//分配掩膜映像空間
          backproject = cvCreateImage( cvGetSize(frame), 8, 1 );//分配反向投影圖空間，大小一樣，單通道
          hist = cvCreateHist( 1, &hdims, CV_HIST_ARRAY, &hranges, 1 ); //分配建立長條圖空間

          histimg = cvCreateImage( cvSize(320,200), 8, 3 );//分配用於畫長條圖的空間
         cvZero( histimg );//背景為黑色
       }

       cvCopy( frame, image, 0 );
       cvCvtColor( image, hsv, CV_BGR2HSV ); // 把映像從RGB表色系轉為HSV表色系

       if( track_object )//   如果當前有需要跟蹤的物體   

      {
             int _vmin = vmin, _vmax = vmax;

             cvInRangeS( hsv, cvScalar(0,smin,MIN(_vmin,_vmax),0),cvScalar(180,256,MAX(_vmin,_vmax),0), mask ); //製作掩膜板，只處理像素值為H：0~180，S：smin~256，V：vmin~vmax之間的部分
             cvSplit( hsv, hue, 0, 0, 0 ); // 取得H分量

             if( track_object < 0 )//如果需要跟蹤的物體還沒有進行屬性提取，則進行選取框類的映像屬性提取
             {
                    float max_val = 0.f;
                   cvSetImageROI( hue, selection ); // 設定原選擇框
                   cvSetImageROI( mask, selection ); // 設定Mask的選擇框

                   cvCalcHist( &hue, hist, 0, mask ); // 得到選擇框內且滿足掩膜板內的長條圖

                   cvGetMinMaxHistValue( hist, 0, &max_val, 0, 0 ); 
                   cvConvertScale( hist->bins, hist->bins, max_val ? 255. / max_val : 0., 0 ); // 對長條圖轉為0~255
                   cvResetImageROI( hue ); // remove ROI
                   cvResetImageROI( mask );
                   track_window = selection;
                   track_object = 1;

                  cvZero( histimg );
                  bin_w = histimg->width / hdims;

                  for( i = 0; i < hdims; i++ )
                  {
                      int val = cvRound(
                      cvGetReal1D(hist->bins,i)*histimg->height/255 );
                      CvScalar color = hsv2rgb(i*180.f/hdims);
                      cvRectangle( histimg, cvPoint(i*bin_w,histimg->height),
                      cvPoint((i+1)*bin_w,histimg->height - val),color, -1, 8, 0 );//畫長條圖到映像空間
                  }
        }

         cvCalcBackProject( &hue, backproject, hist ); // 得到hue的反向投影圖

         cvAnd( backproject, mask, backproject, 0 );得到反向投影圖mask內的內容
         cvCamShift( backproject, track_window,cvTermCriteria( CV_TERMCRIT_EPS | CV_TERMCRIT_ITER, 10, 1 ),&track_comp, &track_box );//使用MeanShift演算法對backproject中的內容進行搜尋，返回跟蹤結果
         track_window = track_comp.rect;//得到跟蹤結果的矩形框

         if( backproject_mode )
                cvCvtColor( backproject, image, CV_GRAY2BGR ); // 顯示模式
         if( image->origin )
         track_box.angle = -track_box.angle;
        cvEllipseBox( image, track_box, CV_RGB(255,0,0), 3, CV_AA, 0 );//畫出跟蹤結果的位置
   }

  if( select_object && selection.width > 0 && selection.height > 0 )//如果正處於物體選擇，畫出選擇框
  {
       cvSetImageROI( image, selection );
       cvXorS( image, cvScalarAll(255), image, 0 );
      cvResetImageROI( image );
  }

  cvShowImage( "CamShiftDemo", image );//顯示視頻和長條圖
  cvShowImage( "Histogram", histimg );

  c = cvWaitKey(10);
  if( c == 27 )
      break;

  switch( c )
  {
     case 'b':
           backproject_mode ^= 1;
           break;
     case 'c':
           track_object = 0;
           cvZero( histimg );
           break;
    case 'h':
          show_hist ^= 1;
          if( !show_hist )
                cvDestroyWindow( "Histogram" );
         else
               cvNamedWindow( "Histogram", 1 );
         break;
    default:
           ;
      }
   }

   cvReleaseCapture( &capture );
   cvDestroyWindow("CamShiftDemo");

    return 0;
}