OpenNI2+Nite2 isNew() isLost() methods in Kinect SDK

Question

I recently switched from OpenNI2+Nite2 confuguration to official Kinect SDK for a project. In nite my code goes like this:

const nite::Array<nite::UserData>& users = frame.getUsers();

for (int i=0; i<users.getSize(); i++){
    const nite::UserData& user = users[i]; 

if(user.isNew()){/* do this */}
if(user.isLost()){/* do that */}
else {/* update*/}

However, I couldn't find a method that does the same thing as isNew & isLost in Kinect SDK. I implemented my own method for isNew, but I failed in isLost.

    // handle user exit
map<string,Group3D*> g3D_copy = g3D;

for(map<string,Group3D*>::iterator mit = g3D_copy.begin();mit != g3D_copy.end();mit++){


    if(mit->second->getType() == "KINECT_SKELETON")
    {
        string groupID = mit->first;
        int countExistance2 = 0;

        for (int i = 0; i < NUI_SKELETON_COUNT; i++){

            int userID = (int)SkeletonFrame.SkeletonData[i].dwTrackingID;
            char buffer [33];
            sprintf(buffer,"%lu",SkeletonFrame.SkeletonData[i].dwTrackingID);
            string myID2 = buffer;
            cout << "groupID " << groupID << endl;
            cout << "myID2 " << myID2 << endl;
            if(myID2 == groupID){ countExistance2++;}       

        }
        // user lost
        if(countExistance2 == 0){
            delete g3D[groupID];
            g3D.erase(groupID);
            cout << "*************deleted*******" << endl;
        }
    }

}

Basicly, I am trying to erase the dedicated slot to a skeleton in a map called g3D in every update of the skeleton frame if the skeleton is lost.

Any ideas or sharp eyes are appreciated.

Answer 1

Finally I solved the problem by counting the frames which do not have a tracked skeleton. Skeleton data has 6 slots and in some frames its tracking id is not set to NUI_SKELETON_TRACKED. Thus, If the number of empty skeleton slots exceeds 20 (which means appx 3-4 successive empty frames), I assume the user is lost.

    // handle user exit
// The skeleton is not tracked in every successive frame, so use g3DCounts to count the number of frames
map<string,Group3D*> g3D_copy = g3D;

for(map<string,Group3D*>::iterator mit = g3D_copy.begin();mit != g3D_copy.end();mit++){

    if(mit->second->getType() == "KINECT_SKELETON")
    {
        string groupID = mit->first;

        for (int i = 0; i < NUI_SKELETON_COUNT; i++){
            char buffer [33];
            sprintf(buffer,"%lu",SkeletonFrame.SkeletonData[i].dwTrackingID);
            string myID2 = buffer;
            if(myID2 == groupID){ g3DCounts[groupID] = 0;}
            else{ g3DCounts[groupID] += 1;}
        }

        if(g3DCounts[groupID] > 20){
            delete g3D[groupID];
            g3D.erase(groupID);
            cout << "*************deleted successfully*******" << endl;
        }
    }
}

Hope it helps others