vpTemplateTrackerWarpHomography.cpp

/*
 * ViSP, open source Visual Servoing Platform software.
 * Copyright (C) 2005 - 2025 by Inria. All rights reserved.
 *
 * This software is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * See the file LICENSE.txt at the root directory of this source
 * distribution for additional information about the GNU GPL.
 *
 * For using ViSP with software that can not be combined with the GNU
 * GPL, please contact Inria about acquiring a ViSP Professional
 * Edition License.
 *
 * See https://visp.inria.fr for more information.
 *
 * This software was developed at:
 * Inria Rennes - Bretagne Atlantique
 * Campus Universitaire de Beaulieu
 * 35042 Rennes Cedex
 * France
 *
 * If you have questions regarding the use of this file, please contact
 * Inria at visp@inria.fr
 *
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Description:
 * Template tracker.
 *
 * Authors:
 * Amaury Dame
 * Aurelien Yol
 */
#include <visp3/core/vpTrackingException.h>
#include <visp3/tt/vpTemplateTrackerWarpHomography.h>
 
BEGIN_VISP_NAMESPACE
  vpTemplateTrackerWarpHomography::vpTemplateTrackerWarpHomography() { nbParam = 8; }

void vpTemplateTrackerWarpHomography::getParamPyramidDown(const vpColVector &p, vpColVector &p_down)
{
  p_down[0] = p[0];
  p_down[1] = p[1];
  p_down[2] = p[2] * 2.;
  p_down[3] = p[3];
  p_down[4] = p[4];
  p_down[5] = p[5] * 2.;
  p_down[6] = p[6] / 2.;
  p_down[7] = p[7] / 2.;
}

void vpTemplateTrackerWarpHomography::getParamPyramidUp(const vpColVector &p, vpColVector &p_up)
{
  p_up[0] = p[0];
  p_up[1] = p[1];
  p_up[2] = p[2] / 2.;
  p_up[3] = p[3];
  p_up[4] = p[4];
  p_up[5] = p[5] / 2.;
  p_up[6] = p[6] * 2.;
  p_up[7] = p[7] * 2.;
}

void vpTemplateTrackerWarpHomography::getdW0(const int &v, const int &u, const double &dv, const double &du,
                                             double *dIdW)
{
  double u_du_ = u * du;
  double v_dv_ = v * dv;
  dIdW[0] = u_du_;
  dIdW[1] = u * dv;
  dIdW[2] = -u * (u_du_ + v_dv_);
  dIdW[3] = v * du;
  dIdW[4] = v_dv_;
  dIdW[5] = -v * (u_du_ + v_dv_);
  dIdW[6] = du;
  dIdW[7] = dv;
}

void vpTemplateTrackerWarpHomography::getdWdp0(const int &v, const int &u, double *dIdW)
{
  double uv_ = u * v;
  dIdW[0] = u;
  dIdW[1] = 0;
  dIdW[2] = -u * u;
  dIdW[3] = v;
  dIdW[4] = 0;
  dIdW[5] = -uv_;
  dIdW[6] = 1.;
  dIdW[7] = 0;
 
  dIdW[8] = 0;
  dIdW[9] = u;
  dIdW[10] = -uv_;
  dIdW[11] = 0;
  dIdW[12] = v;
  dIdW[13] = -v * v;
  dIdW[14] = 0;
  dIdW[15] = 1.;
}

void vpTemplateTrackerWarpHomography::computeDenom(vpColVector &X, const vpColVector &p)
{
  double value = (p[2] * X[0] + p[5] * X[1] + 1.);
 
  if (std::fabs(value) > std::numeric_limits<double>::epsilon()) {
    denom = (1. / value);
  }
  else {
    throw(vpTrackingException(vpTrackingException::fatalError,
                              "Division by zero in vpTemplateTrackerWarpHomography::computeDenom()"));
  }
}

void vpTemplateTrackerWarpHomography::warpX(const int &v1, const int &u1, double &v2, double &u2, const vpColVector &p)
{
  u2 = ((1. + p[0]) * u1 + p[3] * v1 + p[6]) * denom;
  v2 = (p[1] * u1 + (1. + p[4]) * v1 + p[7]) * denom;
}

void vpTemplateTrackerWarpHomography::warpX(const vpColVector &X1, vpColVector &X2, const vpColVector &p)
{
  X2[0] = ((1 + p[0]) * X1[0] + p[3] * X1[1] + p[6]) * denom;
  X2[1] = (p[1] * X1[0] + (1 + p[4]) * X1[1] + p[7]) * denom;
}

void vpTemplateTrackerWarpHomography::dWarp(const vpColVector &X, const vpColVector &, const vpColVector &,
                                            vpMatrix &dM)
{
  double u = X[0];
  double v = X[1];
  dM[0][0] = u * denom;
  dM[0][1] = 0;
  dM[0][2] = -u * X[0] * denom;
  dM[0][3] = v * denom;
  dM[0][4] = 0;
  dM[0][5] = -v * X[0] * denom;
  dM[0][6] = denom;
 
  dM[1][1] = u * denom;
  dM[1][2] = -u * X[1] * denom;
  dM[1][4] = v * denom;
  dM[1][5] = -v * X[1] * denom;
  dM[1][7] = denom;
}

void vpTemplateTrackerWarpHomography::dWarpCompo(const vpColVector &, const vpColVector &X, const vpColVector &p,
                                                 const double *dwdp0, vpMatrix &dM)
{
  double dwdx0, dwdx1;
  double dwdy0, dwdy1;
 
  dwdx0 = ((1. + p[0]) - X[0] * p[2]) * denom;
  dwdx1 = (p[1] - X[1] * p[2]) * denom;
  dwdy0 = (p[3] - X[0] * p[5]) * denom;
  dwdy1 = ((1. + p[4]) - X[1] * p[5]) * denom;
  for (unsigned int i = 0; i < nbParam; i++) {
    dM[0][i] = dwdx0 * dwdp0[i] + dwdy0 * dwdp0[i + nbParam];
    dM[1][i] = dwdx1 * dwdp0[i] + dwdy1 * dwdp0[i + nbParam];
  }
}

void vpTemplateTrackerWarpHomography::warpXInv(const vpColVector &X1, vpColVector &X2, const vpColVector &p)
{
  double value = (p[2] * X1[0] + p[5] * X1[1] + 1.);
 
  if (std::fabs(value) > std::numeric_limits<double>::epsilon()) {
    X2[0] = ((1 + p[0]) * X1[0] + p[3] * X1[1] + p[6]) / value;
    X2[1] = (p[1] * X1[0] + (1 + p[4]) * X1[1] + p[7]) / value;
  }
  else {
    throw(vpTrackingException(vpTrackingException::fatalError, "Division by zero in "
                              "vpTemplateTrackerWarpHomography::"
                              "warpXInv()"));
  }
}

void vpTemplateTrackerWarpHomography::getParamInverse(const vpColVector &p, vpColVector &p_inv) const
{
  double h_00 = 1. + p[0];
  double h_10 = p[1];
  double h_20 = p[2];
  double h_01 = p[3];
  double h_11 = 1. + p[4];
  double h_21 = p[5];
  double h_02 = p[6];
  double h_12 = p[7];
 
  double h_inv_22 = (h_00 * h_11 - h_01 * h_10);
 
  if (std::fabs(h_inv_22) < std::numeric_limits<double>::epsilon()) {
    throw(vpException(vpException::fatalError, "Cannot get homography inverse parameters. Matrix determinant is 0."));
  }
 
  p_inv[0] = (h_11 - h_12 * h_21) / h_inv_22 - 1.;
  p_inv[3] = (h_02 * h_21 - h_01) / h_inv_22;
  p_inv[6] = (h_01 * h_12 - h_02 * h_11) / h_inv_22;
 
  p_inv[1] = (h_12 * h_20 - h_10) / h_inv_22;
  p_inv[4] = (h_00 - h_02 * h_20) / h_inv_22 - 1.;
  p_inv[7] = (h_02 * h_10 - h_00 * h_12) / h_inv_22;
 
  p_inv[2] = (h_10 * h_21 - h_11 * h_20) / h_inv_22;
  p_inv[5] = (h_01 * h_20 - h_00 * h_21) / h_inv_22;
}

vpHomography vpTemplateTrackerWarpHomography::getHomography(const vpColVector &p) const
{
  vpHomography H;
  H[0][0] = 1. + p[0];
  H[1][0] = p[1];
  H[2][0] = p[2];
  H[0][1] = p[3];
  H[1][1] = 1. + p[4];
  H[2][1] = p[5];
  H[0][2] = p[6];
  H[1][2] = p[7];
  H[2][2] = 1.;
 
  return H;
}

void vpTemplateTrackerWarpHomography::getParam(const vpHomography &H, vpColVector &p) const
{
  p.resize(getNbParam(), false);
  p[0] = H[0][0] / H[2][2] - 1.;
  p[1] = H[1][0] / H[2][2];
  p[2] = H[2][0] / H[2][2];
  p[3] = H[0][1] / H[2][2];
  p[4] = H[1][1] / H[2][2] - 1.;
  p[5] = H[2][1] / H[2][2];
  p[6] = H[0][2] / H[2][2];
  p[7] = H[1][2] / H[2][2];
}

void vpTemplateTrackerWarpHomography::getParam(const vpMatrix &H, vpColVector &p) const
{
  p.resize(getNbParam(), false);
  p[0] = H[0][0] / H[2][2] - 1.;
  p[1] = H[1][0] / H[2][2];
  p[2] = H[2][0] / H[2][2];
  p[3] = H[0][1] / H[2][2];
  p[4] = H[1][1] / H[2][2] - 1.;
  p[5] = H[2][1] / H[2][2];
  p[6] = H[0][2] / H[2][2];
  p[7] = H[1][2] / H[2][2];
}

void vpTemplateTrackerWarpHomography::pRondp(const vpColVector &p1, const vpColVector &p2, vpColVector &p12) const
{
  double h1_00 = 1. + p1[0];
  double h1_10 = p1[1];
  double h1_20 = p1[2];
  double h1_01 = p1[3];
  double h1_11 = 1. + p1[4];
  double h1_21 = p1[5];
  double h1_02 = p1[6];
  double h1_12 = p1[7];
 
  double h2_00 = 1. + p2[0];
  double h2_10 = p2[1];
  double h2_20 = p2[2];
  double h2_01 = p2[3];
  double h2_11 = 1. + p2[4];
  double h2_21 = p2[5];
  double h2_02 = p2[6];
  double h2_12 = p2[7];
 
  double h12_22 = h1_20 * h2_02 + h1_21 * h2_12 + 1.;
 
  p12[0] = (h1_00 * h2_00 + h1_01 * h2_10 + h1_02 * h2_20) / h12_22 - 1.;
  p12[3] = (h1_00 * h2_01 + h1_01 * h2_11 + h1_02 * h2_21) / h12_22;
  p12[6] = (h1_00 * h2_02 + h1_01 * h2_12 + h1_02) / h12_22;
 
  p12[1] = (h1_10 * h2_00 + h1_11 * h2_10 + h1_12 * h2_20) / h12_22;
  p12[4] = (h1_10 * h2_01 + h1_11 * h2_11 + h1_12 * h2_21) / h12_22 - 1.;
  p12[7] = (h1_10 * h2_02 + h1_11 * h2_12 + h1_12) / h12_22;
 
  p12[2] = (h1_20 * h2_00 + h1_21 * h2_10 + h2_20) / h12_22;
  p12[5] = (h1_20 * h2_01 + h1_21 * h2_11 + h2_21) / h12_22;
}
END_VISP_NAMESPACE