void LocalMapping::KeyFrameCulling()
{
// Check redundant keyframes (only local keyframes)
// A keyframe is considered redundant if the 90% of the MapPoints it sees, are seen
// in at least other 3 keyframes (in the same or finer scale)
vector<KeyFrame*> vpLocalKeyFrames = mpCurrentKeyFrame->GetVectorCovisibleKeyFrames();
for(vector<KeyFrame*>::iterator vit=vpLocalKeyFrames.begin(), vend=vpLocalKeyFrames.end(); vit!=vend; vit++)
{
KeyFrame* pKF = *vit;
if(pKF->mnId==0)
continue;
vector<MapPoint*> vpMapPoints = pKF->GetMapPointMatches();
int nRedundantObservations=0;
int nMPs=0;
for(size_t i=0, iend=vpMapPoints.size(); i<iend; i++)
{
MapPoint* pMP = vpMapPoints[i];
if(pMP)
{
if(!pMP->isBad())
{
nMPs++;
if(pMP->Observations()>3)
{
int scaleLevel = pKF->GetKeyPointUn(i).octave;
map<KeyFrame*, size_t> observations = pMP->GetObservations();
int nObs=0;
for(map<KeyFrame*, size_t>::iterator mit=observations.begin(), mend=observations.end(); mit!=mend; mit++)
{
KeyFrame* pKFi = mit->first;
if(pKFi==pKF)
continue;
int scaleLeveli = pKFi->GetKeyPointUn(mit->second).octave;
if(scaleLeveli<=scaleLevel+1)
{
nObs++;
if(nObs>=3)
break;
}
}
if(nObs>=3)
{
nRedundantObservations++;
}
}
}
}
}
if(nRedundantObservations>0.9*nMPs)
pKF->SetBadFlag();
}
}
void KeyFrame::UpdateConnections()
{
map<KeyFrame*,int> KFcounter;
vector<MapPoint*> vpMP;
{
boost::mutex::scoped_lock lockMPs(mMutexFeatures);
vpMP = mvpMapPoints;
}
//For all map points in keyframe check in which other keyframes are they seen
//Increase counter for those keyframes
for(vector<MapPoint*>::iterator vit=vpMP.begin(), vend=vpMP.end(); vit!=vend; vit++)
{
MapPoint* pMP = *vit;
if(!pMP)
continue;
if(pMP->isBad())
continue;
map<KeyFrame*,size_t> observations = pMP->GetObservations();
for(map<KeyFrame*,size_t>::iterator mit=observations.begin(), mend=observations.end(); mit!=mend; mit++)
{
if(mit->first->mnId==mnId)
continue;
KFcounter[mit->first]++;
}
}
if(KFcounter.empty())
return;
//If the counter is greater than threshold add connection
//In case no keyframe counter is over threshold add the one with maximum counter
int nmax=0;
KeyFrame* pKFmax=NULL;
int th = 15;
vector<pair<int,KeyFrame*> > vPairs;
vPairs.reserve(KFcounter.size());
for(map<KeyFrame*,int>::iterator mit=KFcounter.begin(), mend=KFcounter.end(); mit!=mend; mit++)
{
if(mit->second>nmax)
{
nmax=mit->second;
pKFmax=mit->first;
}
if(mit->second>=th)
{
vPairs.push_back(make_pair(mit->second,mit->first));
(mit->first)->AddConnection(this,mit->second);
}
}
if(vPairs.empty())
{
vPairs.push_back(make_pair(nmax,pKFmax));
pKFmax->AddConnection(this,nmax);
}
sort(vPairs.begin(),vPairs.end());
list<KeyFrame*> lKFs;
list<int> lWs;
for(size_t i=0; i<vPairs.size();i++)
{
lKFs.push_front(vPairs[i].second);
lWs.push_front(vPairs[i].first);
}
{
boost::mutex::scoped_lock lockCon(mMutexConnections);
// mspConnectedKeyFrames = spConnectedKeyFrames;
mConnectedKeyFrameWeights = KFcounter;
mvpOrderedConnectedKeyFrames = vector<KeyFrame*>(lKFs.begin(),lKFs.end());
mvOrderedWeights = vector<int>(lWs.begin(), lWs.end());
if(mbFirstConnection && mnId!=0)
{
mpParent = mvpOrderedConnectedKeyFrames.front();
mpParent->AddChild(this);
mbFirstConnection = false;
}
}
}
