Method OptimizeEssentialGraph

src/Optimizer.cc:1501–1783

void Optimizer::OptimizeEssentialGraph(Map* pMap, KeyFrame* pLoopKF, KeyFrame* pCurKF,
                                       const LoopClosing::KeyFrameAndPose &NonCorrectedSim3,
                                       const LoopClosing::KeyFrameAndPose &CorrectedSim3,
                                       const map<KeyFrame *, set<KeyFrame *> > &LoopConnections, const bool &bFixScale)
{   
    // Setup optimizer
    g2o::SparseOptimizer optimizer;
    optimizer.setVerbose(false);
    g2o::BlockSolver_7_3::LinearSolverType * linearSolver =
           new g2o::LinearSolverEigen<g2o::BlockSolver_7_3::PoseMatrixType>();
    g2o::BlockSolver_7_3 * solver_ptr= new g2o::BlockSolver_7_3(linearSolver);
    g2o::OptimizationAlgorithmLevenberg* solver = new g2o::OptimizationAlgorithmLevenberg(solver_ptr);

    solver->setUserLambdaInit(1e-16);
    optimizer.setAlgorithm(solver);

    const vector<KeyFrame*> vpKFs = pMap->GetAllKeyFrames();
    const vector<MapPoint*> vpMPs = pMap->GetAllMapPoints();

    const unsigned int nMaxKFid = pMap->GetMaxKFid();

    vector<g2o::Sim3,Eigen::aligned_allocator<g2o::Sim3> > vScw(nMaxKFid+1);
    vector<g2o::Sim3,Eigen::aligned_allocator<g2o::Sim3> > vCorrectedSwc(nMaxKFid+1);
    vector<g2o::VertexSim3Expmap*> vpVertices(nMaxKFid+1);

    vector<Eigen::Vector3d> vZvectors(nMaxKFid+1); // For debugging
    Eigen::Vector3d z_vec;
    z_vec << 0.0, 0.0, 1.0;

    const int minFeat = 100;

    // Set KeyFrame vertices
    for(size_t i=0, iend=vpKFs.size(); i<iend;i++)
    {
        KeyFrame* pKF = vpKFs[i];
        if(pKF->isBad())
            continue;
        g2o::VertexSim3Expmap* VSim3 = new g2o::VertexSim3Expmap();

        const int nIDi = pKF->mnId;

        LoopClosing::KeyFrameAndPose::const_iterator it = CorrectedSim3.find(pKF);

        if(it!=CorrectedSim3.end())
        {
            vScw[nIDi] = it->second;
            VSim3->setEstimate(it->second);
        }
        else
        {
            Sophus::SE3d Tcw = pKF->GetPose().cast<double>();
            g2o::Sim3 Siw(Tcw.unit_quaternion(),Tcw.translation(),1.0);
            vScw[nIDi] = Siw;
            VSim3->setEstimate(Siw);
        }

        if(pKF->mnId==pMap->GetInitKFid())
            VSim3->setFixed(true);