Homography.h

#ifndef MTF_HOMOGRAPHY_H
#define MTF_HOMOGRAPHY_H

#include "ProjectiveBase.h"

_MTF_BEGIN_NAMESPACE

struct HomographyParams : SSMParams{
    // use normalized unit square points/corners as the initial points/corners
    bool normalized_init;   
    // generate samples by ading perturbations directly to the corners
    // and using DLT method to estimate the corresponding warp
    bool corner_based_sampling;
    bool debug_mode;

    HomographyParams(const SSMParams *ssm_params,
        bool _normalized_init,
        bool _corner_based_sampling, bool _debug_mode);
    HomographyParams(const HomographyParams *params = nullptr);
};

class Homography : public ProjectiveBase{
public:
    
    typedef HomographyParams ParamType;
    using ProjectiveBase::setCorners;

    Homography( const ParamType *params_in = nullptr);
    void compositionalUpdate(const VectorXd& state_update) override;

    void cmptInitPixJacobian(MatrixXd &jacobian_prod, const PixGradT &am_jacobian) override;
    void cmptPixJacobian(MatrixXd &jacobian_prod, const PixGradT &am_jacobian) override;
    void cmptWarpedPixJacobian(MatrixXd &jacobian_prod,
        const PixGradT &pix_jacobian) override;

    void cmptApproxPixJacobian(MatrixXd &jacobian_prod,
        const PixGradT &pix_jacobian) override;
    void estimateWarpFromCorners(VectorXd &state_update, const CornersT &in_corners,
        const CornersT &out_corners) override;
    void cmptInitPixHessian(MatrixXd &pix_hess_ssm, const PixHessT &pix_hess_coord,
        const PixGradT &pix_grad) override;

    void cmptWarpedPixHessian(MatrixXd &pix_hess_ssm, const PixHessT &pix_hess_coord,
        const PixGradT &pix_grad) override;
    void cmptWarpedPixHessian2(MatrixXd &pix_hess_ssm, const PixHessT &pix_hess_coord,
        const PixGradT &pix_grad);
    void cmptApproxPixHessian(MatrixXd &pix_hess_ssm, const PixHessT &pix_hess_coord,
        const PixGradT &pix_grad) override;
    void cmptPixHessian(MatrixXd &pix_hess_ssm, const PixHessT &pix_hess_coord,
        const PixGradT &pix_grad) override;

    void setCorners(const CornersT& corners) override;
    void estimateWarpFromPts(VectorXd &state_update, vector<uchar> &mask,
        const vector<cv::Point2f> &in_pts, const vector<cv::Point2f> &out_pts,
        const EstimatorParams &est_params) override;

    void invertState(VectorXd& inv_state, const VectorXd& state) override;

    void updateGradPts(double grad_eps) override;
    void updateHessPts(double hess_eps) override;

    void getInitPixGrad(Matrix2Xd &jacobian_prod, int pix_id) override;
    void getCurrPixGrad(Matrix2Xd &jacobian_prod, int pix_id) override;

    void generatePerturbation(VectorXd &state_update) override;
    void compositionalRandomWalk(VectorXd &perturbed_state,
        const VectorXd &base_state) override;
    void compositionalAutoRegression1(VectorXd &perturbed_state, VectorXd &perturbed_ar,
        const VectorXd &base_state, const VectorXd &base_ar, double a = 0.5) override;

    void getWarpFromState(Matrix3d &warp_mat, const VectorXd& ssm_state) override;
    void getStateFromWarp(VectorXd &state_vec, const Matrix3d& warp_mat) override;

#ifndef DISABLE_SPI
    bool supportsSPI() override{ return true; }
#endif

private:
    ParamType params;

    CornersT rand_d;
    Vector2d rand_t;
    CornersT disturbed_corners;
};

_MTF_END_NAMESPACE

#endif