How can I track many blobs in occlusion, Opencv C++ - c++

Question

I am trying to develop an algorithm which tracks two hands. I need to handle the occlusion problem. I have used the CvBlobs for this.
Do you have a solution ?

Answer 1

I think you need to use some machine learning algorithm

Answer 2

Try cvStartFindContours() and cvFindNextContour()
Found a few good links:
OpenCV HAND DETECTION code: http://download.andol.info/hsv.cpp
color object tracking in openCV keeps detecting the skin
Hand gesture: http://www.andol.info/hci/895.htm
//VERSION: HAND DETECTION 1.0
//AUTHOR: ANDOL LI#CW3/18, Live:lab
//PROJECT: HAND DETECTION PROTOTYPE
//LAST UPDATED: 03/2009
#include "cv.h"
#include "cxcore.h"
#include "highgui.h"
#include "math.h"
#include <iostream>
#include <stdio.h>
#include <string.h>
#include <conio.h>
#include <sstream>
#include <time.h>
using namespace std;
/*
--------------------------------------------*/
int main()
{
int c = 0;
CvSeq* a = 0;
CvCapture* capture = cvCaptureFromCAM(0);
if(!cvQueryFrame(capture)){ cout<<"Video capture failed, please check the camera."<<endl;}else{cout<<"Video camera capture status: OK"<<endl;};
CvSize sz = cvGetSize(cvQueryFrame( capture));
IplImage* src = cvCreateImage( sz, 8, 3 );
IplImage* hsv_image = cvCreateImage( sz, 8, 3);
IplImage* hsv_mask = cvCreateImage( sz, 8, 1);
IplImage* hsv_edge = cvCreateImage( sz, 8, 1);
CvScalar hsv_min = cvScalar(0, 30, 80, 0);
CvScalar hsv_max = cvScalar(20, 150, 255, 0);
//
CvMemStorage* storage = cvCreateMemStorage(0);
CvMemStorage* areastorage = cvCreateMemStorage(0);
CvMemStorage* minStorage = cvCreateMemStorage(0);
CvMemStorage* dftStorage = cvCreateMemStorage(0);
CvSeq* contours = NULL;
//
cvNamedWindow( "src",1);
//cvNamedWindow( "hsv-msk",1);
//cvNamedWindow( "contour",1);
//////
while( c != 27)
{
IplImage* bg = cvCreateImage( sz, 8, 3);
cvRectangle( bg, cvPoint(0,0), cvPoint(bg->width,bg->height), CV_RGB( 255, 255, 255), -1, 8, 0 );
bg->origin = 1;
for(int b = 0; b< int(bg->width/10); b++)
{
cvLine( bg, cvPoint(b*20, 0), cvPoint(b*20, bg->height), CV_RGB( 200, 200, 200), 1, 8, 0 );
cvLine( bg, cvPoint(0, b*20), cvPoint(bg->width, b*20), CV_RGB( 200, 200, 200), 1, 8, 0 );
}
src = cvQueryFrame( capture);
cvCvtColor(src, hsv_image, CV_BGR2HSV);
cvInRangeS (hsv_image, hsv_min, hsv_max, hsv_mask);
cvSmooth( hsv_mask, hsv_mask, CV_MEDIAN, 27, 0, 0, 0 );
cvCanny(hsv_mask, hsv_edge, 1, 3, 5);
cvFindContours( hsv_mask, storage, &contours, sizeof(CvContour), CV_RETR_LIST, CV_CHAIN_APPROX_SIMPLE, cvPoint(0,0) );
CvSeq* contours2 = NULL;
double result = 0, result2 = 0;
while(contours)
{
result = fabs( cvContourArea( contours, CV_WHOLE_SEQ ) );
if ( result > result2) {result2 = result; contours2 = contours;};
contours = contours->h_next;
}
if ( contours2 )
{
//cout << "contours2: " << contours2->total << endl;
CvRect rect = cvBoundingRect( contours2, 0 );
cvRectangle( bg, cvPoint(rect.x, rect.y + rect.height), cvPoint(rect.x + rect.width, rect.y), CV_RGB(200, 0, 200), 1, 8, 0 );
//cout << "Ratio: " << rect.width << ", " << rect.height << ", " << (float)rect.width / rect.height << endl;
int checkcxt = cvCheckContourConvexity( contours2 );
//cout << checkcxt <<endl;
CvSeq* hull = cvConvexHull2( contours2, 0, CV_CLOCKWISE, 0 );
CvSeq* defect = cvConvexityDefects( contours2, hull, dftStorage );
if( defect->total >=40 ) {cout << " Closed Palm " << endl;}
else if( defect->total >=30 && defect->total <40 ) {cout << " Open Palm " << endl;}
else{ cout << " Fist " << endl;}
cout << "defet: " << defect->total << endl;
CvBox2D box = cvMinAreaRect2( contours2, minStorage );
//cout << "box angle: " << (int)box.angle << endl;
cvCircle( bg, cvPoint(box.center.x, box.center.y), 3, CV_RGB(200, 0, 200), 2, 8, 0 );
cvEllipse( bg, cvPoint(box.center.x, box.center.y), cvSize(box.size.height/2, box.size.width/2), box.angle, 0, 360, CV_RGB(220, 0, 220), 1, 8, 0 );
//cout << "Ratio: " << (float)box.size.width/box.size.height <<endl;
}
//cvShowImage( "hsv-msk", hsv_mask); hsv_mask->origin = 1;
//IplImage* contour = cvCreateImage( sz, 8, 3 );
cvDrawContours( bg, contours2, CV_RGB( 0, 200, 0), CV_RGB( 0, 100, 0), 1, 1, 8, cvPoint(0,0));
cvShowImage( "src", src);
//contour->origin = 1; cvShowImage( "contour", contour);
//cvReleaseImage( &contour);
cvNamedWindow("bg",0);
cvShowImage("bg",bg);
cvReleaseImage( &bg);
c = cvWaitKey( 10);
}
//////
cvReleaseCapture( &capture);
cvDestroyAllWindows();
}