vpMeterPixelConversion.cpp

/****************************************************************************
 *
 * This file is part of the ViSP software.
 * Copyright (C) 2005 - 2017 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:
 * Meter to pixel conversion.
 *
 * Authors:
 * Eric Marchand
 * Anthony Saunier
 *
 *****************************************************************************/

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

void vpMeterPixelConversion::convertLine(const vpCameraParameters &cam, const double &rho_m, const double &theta_m,
                                         double &rho_p, double &theta_p)
{
  double co = cos(theta_m);
  double si = sin(theta_m);
  double d = sqrt(vpMath::sqr(cam.py * co) + vpMath::sqr(cam.px * si));

  if (fabs(d) < 1e-6) {
    vpERROR_TRACE("division by zero");
    throw(vpException(vpException::divideByZeroError, "division by zero"));
  }

  theta_p = atan2(cam.px * si, cam.py * co);
  rho_p = (cam.px * cam.py * rho_m + cam.u0 * cam.py * co + cam.v0 * cam.px * si);
  rho_p /= d;
}

void vpMeterPixelConversion::convertEllipse(const vpCameraParameters &cam, const vpCircle &circle, vpImagePoint &center,
                                            double &mu20_p, double &mu11_p, double &mu02_p)
{
  // Get the parameters of the ellipse in the image plane
  double xc_m = circle.p[0];
  double yc_m = circle.p[1];
  double mu20_m = circle.p[2];
  double mu11_m = circle.p[3];
  double mu02_m = circle.p[4];

  // Convert from meter to pixels
  vpMeterPixelConversion::convertPoint(cam, xc_m, yc_m, center);
  mu20_p = mu20_m * vpMath::sqr(cam.get_px());
  mu11_p = mu11_m * cam.get_px() * cam.get_py();
  mu02_p = mu02_m * vpMath::sqr(cam.get_py());
}