vpPixelMeterConversion.h

/****************************************************************************
 *
 * ViSP, open source Visual Servoing Platform software.
 * Copyright (C) 2005 - 2019 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 http://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:
 * Pixel to meter conversion.
 *
 * Authors:
 * Eric Marchand
 * Anthony Saunier
 *
 *****************************************************************************/

#ifndef vpPixelMeterConversion_H
#define vpPixelMeterConversion_H

#include <visp3/core/vpCameraParameters.h>
#include <visp3/core/vpDebug.h>
#include <visp3/core/vpException.h>
#include <visp3/core/vpImagePoint.h>
#include <visp3/core/vpMath.h>

#if VISP_HAVE_OPENCV_VERSION >= 0x020300
#  include <opencv2/imgproc/imgproc.hpp>
#  include <opencv2/calib3d/calib3d.hpp>
#endif

class VISP_EXPORT vpPixelMeterConversion
{
public:
  static void convertEllipse(const vpCameraParameters &cam,
                             const vpImagePoint &center_p, double n20_p, double n11_p, double n02_p,
                             double &xc_m, double &yc_m, double &n20_m, double &n11_m, double &n02_m);
  static void convertLine(const vpCameraParameters &cam, const double &rho_p, const double &theta_p, double &rho_m,
                          double &theta_m);

  static void convertMoment(const vpCameraParameters &cam, unsigned int order, const vpMatrix &moment_pixel,
                            vpMatrix &moment_meter);
  inline static void convertPoint(const vpCameraParameters &cam,
                                  const double &u, const double &v, double &x, double &y)
  {
    switch (cam.projModel) {
    case vpCameraParameters::perspectiveProjWithoutDistortion:
      convertPointWithoutDistortion(cam, u, v, x, y);
      break;
    case vpCameraParameters::perspectiveProjWithDistortion:
      convertPointWithDistortion(cam, u, v, x, y);
      break;
    case vpCameraParameters::ProjWithKannalaBrandtDistortion:
      convertPointWithKannalaBrandtDistortion(cam, u, v, x, y);
      break;
    }
  }

  inline static void convertPoint(const vpCameraParameters &cam,
                                  const vpImagePoint &iP, double &x, double &y)
  {
    switch (cam.projModel) {
    case vpCameraParameters::perspectiveProjWithoutDistortion:
      convertPointWithoutDistortion(cam, iP, x, y);
      break;
    case vpCameraParameters::perspectiveProjWithDistortion:
      convertPointWithDistortion(cam, iP, x, y);
      break;
    case vpCameraParameters::ProjWithKannalaBrandtDistortion:
      convertPointWithKannalaBrandtDistortion(cam, iP, x, y);
      break;
    }
  }

#ifndef DOXYGEN_SHOULD_SKIP_THIS

  inline static void convertPointWithoutDistortion(const vpCameraParameters &cam,
                                                   const double &u, const double &v, double &x, double &y)
  {
    x = (u - cam.u0) * cam.inv_px;
    y = (v - cam.v0) * cam.inv_py;
  }

  inline static void convertPointWithoutDistortion(const vpCameraParameters &cam,
                                                   const vpImagePoint &iP, double &x, double &y)
  {
    x = (iP.get_u() - cam.u0) * cam.inv_px;
    y = (iP.get_v() - cam.v0) * cam.inv_py;
  }

  inline static void convertPointWithDistortion(const vpCameraParameters &cam,
                                                const double &u, const double &v, double &x, double &y)
  {
    double r2 = 1. + cam.kdu * (vpMath::sqr((u - cam.u0) * cam.inv_px) + vpMath::sqr((v - cam.v0) * cam.inv_py));
    x = (u - cam.u0) * r2 * cam.inv_px;
    y = (v - cam.v0) * r2 * cam.inv_py;
  }

  inline static void convertPointWithDistortion(const vpCameraParameters &cam,
                                                const vpImagePoint &iP, double &x, double &y)
  {
    double r2 = 1. + cam.kdu * (vpMath::sqr((iP.get_u() - cam.u0) * cam.inv_px) +
                                vpMath::sqr((iP.get_v() - cam.v0) * cam.inv_py));
    x = (iP.get_u() - cam.u0) * r2 * cam.inv_px;
    y = (iP.get_v() - cam.v0) * r2 * cam.inv_py;
  }

  inline static void convertPointWithKannalaBrandtDistortion(const vpCameraParameters &cam, const double &u,
                                                             const double &v, double &x, double &y)
  {
    double x_d = (u - cam.u0) / cam.px, y_d = (v - cam.v0) / cam.py;
    double scale = 1.0;
    double r_d = sqrt(vpMath::sqr(x_d) + vpMath::sqr(y_d));

    r_d = std::min(std::max(-M_PI, r_d), M_PI); // FOV restricted to 180degrees.

    std::vector<double> k = cam.getKannalaBrandtDistortionCoefficients();

    const double EPS = 1e-8;
    // Use Newton-Raphson method to solve for the angle theta
    if (r_d > EPS)
    {
      // compensate distortion iteratively
      double theta = r_d;

      for (int j = 0; j < 10; j++)
      {
        double theta2 = theta*theta, theta4 = theta2*theta2, theta6 = theta4*theta2, theta8 = theta6*theta2;
        double k0_theta2 = k[0] * theta2, k1_theta4 = k[1] * theta4, k2_theta6 = k[2] * theta6, k3_theta8 = k[3] * theta8;
        /* new_theta = theta - theta_fix, theta_fix = f0(theta) / f0'(theta) */
        double theta_fix = (theta * (1 + k0_theta2 + k1_theta4 + k2_theta6 + k3_theta8) - r_d) /
                            (1 + 3*k0_theta2 + 5*k1_theta4 + 7*k2_theta6 + 9*k3_theta8);
        theta = theta - theta_fix;
        if (fabs(theta_fix) < EPS)
            break;
      }

      scale = std::tan(theta) / r_d; // Scale of norm of (x,y) and (x_d, y_d)
    }

    x = x_d * scale;
    y = y_d * scale;
  }

  inline static void convertPointWithKannalaBrandtDistortion(const vpCameraParameters &cam, const vpImagePoint &iP,
                                                             double &x, double &y)
  {
    double x_d = (iP.get_u() - cam.u0) / cam.px, y_d = (iP.get_v() - cam.v0) / cam.py;
    double scale = 1.0;
    double r_d = sqrt(vpMath::sqr(x_d) + vpMath::sqr(y_d));

    r_d = std::min(std::max(-M_PI, r_d), M_PI); // FOV restricted to 180degrees.

    std::vector<double> k = cam.getKannalaBrandtDistortionCoefficients();

    const double EPS = 1e-8;
    // Use Newton-Raphson method to solve for the angle theta
    if (r_d > EPS)
    {
      // compensate distortion iteratively
      double theta = r_d;

      for (int j = 0; j < 10; j++)
      {
        double theta2 = theta*theta, theta4 = theta2*theta2, theta6 = theta4*theta2, theta8 = theta6*theta2;
        double k0_theta2 = k[0] * theta2, k1_theta4 = k[1] * theta4, k2_theta6 = k[2] * theta6, k3_theta8 = k[3] * theta8;
        /* new_theta = theta - theta_fix, theta_fix = f0(theta) / f0'(theta) */
        double theta_fix = (theta * (1 + k0_theta2 + k1_theta4 + k2_theta6 + k3_theta8) - r_d) /
                            (1 + 3*k0_theta2 + 5*k1_theta4 + 7*k2_theta6 + 9*k3_theta8);
        theta = theta - theta_fix;
        if (fabs(theta_fix) < EPS)
            break;
      }

      scale = std::tan(theta) / r_d; // Scale of norm of (x,y) and (x_d, y_d)
    }

    x = x_d * scale;
    y = y_d * scale;
  }
#endif // #ifndef DOXYGEN_SHOULD_SKIP_THIS


#if VISP_HAVE_OPENCV_VERSION >= 0x020300

  static void convertEllipse(const cv::Mat &cameraMatrix, const cv::Mat &distCoeffs,
                             const vpImagePoint &center_p, double n20_p, double n11_p, double n02_p,
                             double &xc_m, double &yc_m, double &n20_m, double &n11_m, double &n02_m);
  static void convertLine(const cv::Mat &cameraMatrix,
                          const double &rho_p, const double &theta_p,
                          double &rho_m, double &theta_m);
  static void convertMoment(const cv::Mat &cameraMatrix,
                            unsigned int order, const vpMatrix &moment_pixel,
                            vpMatrix &moment_meter);
  static void convertPoint(const cv::Mat &cameraMatrix, const cv::Mat &distCoeffs,
                           const double &u, const double &v, double &x, double &y);
  static void convertPoint(const cv::Mat &cameraMatrix, const cv::Mat &distCoeffs,
                           const vpImagePoint &iP, double &x, double &y);
#endif
};

#endif