NGF.h

#ifndef MTF_NGF_H
#define MTF_NGF_H

#include "AppearanceModel.h"
#include <Eigen/Sparse>

_MTF_BEGIN_NAMESPACE

struct NGFParams : AMParams{
    double eta;
    bool use_ssd;
    NGFParams(const AMParams *am_params,
        double _eta, bool _use_ssd);
    NGFParams(const NGFParams *params = nullptr);
};

struct NGFDist : AMDist{
    typedef double ElementType;
    typedef double ResultType;
    NGFDist(const string &_name, const bool _use_ssd,
        const unsigned int _patch_size);
    double operator()(const double* a, const double* b,
        size_t size, double worst_dist = -1) const override;
private:
    const bool use_ssd;
    const unsigned int patch_size;
};

class NGF : public AppearanceModel{
public:
    typedef NGFParams ParamType;
    typedef NGFDist DistType;
    typedef SparseMatrix<double> SpMat;
    typedef Triplet<double> SpTr;

    NGF(const ParamType *ngf_params = nullptr, const int _n_channels = 1);

    double getLikelihood() const override;

    //-------------------------------initialize functions------------------------------------//
    void initializePixVals(const Matrix2Xd& init_pts) override;
    void initializeSimilarity() override;
    void initializeGrad() override;
    void initializeHess() override{}

    //-------------------------------update functions------------------------------------//
    void updatePixVals(const Matrix2Xd& curr_pts) override;
    void updateSimilarity(bool prereq_only = true) override;
    void updateInitGrad() override;
    void updateCurrGrad() override;

    //-------------------------------interfacing functions------------------------------------//
    void cmptSelfHessian(MatrixXd &self_hessian, const MatrixXd &curr_pix_jacobian) override;
    void cmptSelfHessian(MatrixXd &self_hessian, const MatrixXd &curr_pix_jacobian,
        const MatrixXd &curr_pix_hessian) override{
        cmptSelfHessian(self_hessian, curr_pix_jacobian);
    };

    // -------------------- distance feature functions -------------------- //
    int feat_size;
    VectorXd curr_feat_vec;
    const DistType* getDistFunc() override{
        return new DistType(name, params.use_ssd, patch_size);
    }
    unsigned int getDistFeatSize() override{ return feat_size; }
    void initializeDistFeat() override;
    void updateDistFeat(double* feat_addr) override;
    const double* getDistFeat() override{ return curr_feat_vec.data(); }
    void updateDistFeat() override{ updateDistFeat(curr_feat_vec.data()); }

protected:
    ParamType params;
    double epsilon;

    PixGradT norm_dI0_dx, norm_dIt_dx;
    Matrix2Xd _init_pts, _curr_pts;
    VectorXd fac_t, fac_0, rc;
    SpMat dr_dIt, dr_dI0;
    VectorXd grad_I0_x, grad_I0_y, grad_It_x, grad_It_y;
    VectorXd grad_I0_norm, grad_It_norm;
    VectorXd grad_I0_squared_norm, grad_It_squared_norm;

};

_MTF_END_NAMESPACE

#endif