MI.h

#ifndef MTF_MI_H
#define MTF_MI_H

#include "AppearanceModel.h"

_MTF_BEGIN_NAMESPACE

struct MIParams : AMParams{
    int n_bins; 
    double pre_seed;
    bool partition_of_unity;
    ImageBase *pix_mapper;

    bool debug_mode; 

    MIParams(const AMParams *am_params,
        int _n_bins, double _pre_seed,
        bool _partition_of_unity,       
        ImageBase *_pix_mapper,
        bool _debug_mode);
    MIParams(const MIParams *params = nullptr);
};

struct MIDist : AMDist{
    typedef double ElementType;
    typedef double ResultType;
    MIDist(const string &_name, const int _n_bins,
        const unsigned int _feat_size, const unsigned int _patch_size,
        const double _hist_pre_seed, const double _pre_seed,
        const MatrixX2i *_std_bspl_ids,
        const double _log_hist_norm_mult);
    double operator()(const double* a, const double* b,
        size_t size, double worst_dist = -1) const override;
private:
    const int n_bins;
    const unsigned int feat_size;
    const unsigned int patch_size;
    const double pre_seed, hist_pre_seed;
    const MatrixX2i *std_bspl_ids;
    const double log_hist_norm_mult;
};

class MI : public AppearanceModel{
public:

    typedef MIParams ParamType;
    typedef MIDist DistType;

    MI(const ParamType *mi_params = nullptr, const int _n_channels = 1);

    double getLikelihood() const override;

    void initializePixVals(const Matrix2Xd& init_pts) override;
    void initializeSimilarity() override;
    void initializeGrad() override;
    void initializeHess() override;

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

    void cmptInitHessian(MatrixXd &hessian, const MatrixXd &curr_pix_jacobian) override;
    void cmptCurrHessian(MatrixXd &hessian, const MatrixXd &curr_pix_jacobian) override;

    void cmptInitHessian(MatrixXd &init_hessian, const MatrixXd &init_pix_jacobian,
        const MatrixXd &init_pix_hessian) override;
    void cmptCurrHessian(MatrixXd &curr_hessian, const MatrixXd &curr_pix_jacobian,
        const MatrixXd &curr_pix_hessian) override;

    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;

    //static const utils::BSpline3WithDiffPtr bSpline3_arr[4];

    //-----------------------------------functor support-----------------------------------//
    const DistType* getDistFunc() override{
        return new DistType(name, params.n_bins, feat_size,
            patch_size, hist_pre_seed, params.pre_seed, 
            &std_bspl_ids, log_hist_norm_mult);
    }
    void initializeDistFeat() override{
        feat_vec.resize(feat_size);
    }
    void updateDistFeat() override{
        updateDistFeat(feat_vec.data());
    }
    const double* getDistFeat() override{ return feat_vec.data(); }
    void updateDistFeat(double* feat_addr) override;
    unsigned int getDistFeatSize() override{ return feat_size; }

private:
    ParamType params;

    char *log_fname;
    char *time_fname;

    double max_similarity;

    double hist_pre_seed;
    double hist_norm_mult;
    unsigned int joint_hist_size;

    // let A = joint_hist_size = n_bins*n_bins and N = n_pix = no. of pixels
    MatrixXd joint_hist;
    VectorXd init_hist, curr_hist;
    MatrixXd init_hist_mat, curr_hist_mat;

    MatrixXd init_joint_hist_grad, curr_joint_hist_grad;
    MatrixXd init_hist_grad, curr_hist_grad;
    MatrixXd init_hist_hess, curr_hist_hess;
    MatrixXd init_grad_factor, curr_grad_factor;

    VectorXd init_hist_log, curr_hist_log;
    MatrixXd joint_hist_log;

    MatrixXd self_joint_hist, self_joint_hist_log;
    MatrixXd self_grad_factor;

    unsigned int feat_size;
    VectorXd feat_vec;
    double log_hist_norm_mult;

    // only used internally to increase speed by offlining as many computations as possible;
    MatrixX2i std_bspl_ids;
    MatrixX2i init_bspl_ids;
    MatrixX2i curr_bspl_ids;
    MatrixXi linear_idx;

    void cmptSelfHist();
};

_MTF_END_NAMESPACE

#endif