transformation_estimation_2D.hpp

/*
 * Software License Agreement (BSD License)
 *
 *  Point Cloud Library (PCL) - www.pointclouds.org
 *  Copyright (c) 2012-, Open Perception Inc.
 *
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials provided
 *     with the distribution.
 *   * Neither the name of the copyright holder(s) nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 *  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 *  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 *  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY OF SUCH DAMAGE.
 *
 */
 
#ifndef PCL_REGISTRATION_TRANSFORMATION_ESTIMATION_2D_HPP_
#define PCL_REGISTRATION_TRANSFORMATION_ESTIMATION_2D_HPP_
 
namespace pcl {
 
namespace registration {
 
template <typename PointSource, typename PointTarget, typename Scalar>
inline void
TransformationEstimation2D<PointSource, PointTarget, Scalar>::
    estimateRigidTransformation(const pcl::PointCloud<PointSource>& cloud_src,
                                const pcl::PointCloud<PointTarget>& cloud_tgt,
                                Matrix4& transformation_matrix) const
{
  const auto nr_points = cloud_src.size();
  if (cloud_tgt.size() != nr_points) {
    PCL_ERROR("[pcl::TransformationEstimation2D::estimateRigidTransformation] Number "
              "or points in source (%zu) differs than target (%zu)!\n",
              static_cast<std::size_t>(nr_points),
              static_cast<std::size_t>(cloud_tgt.size()));
    return;
  }
 
  ConstCloudIterator<PointSource> source_it(cloud_src);
  ConstCloudIterator<PointTarget> target_it(cloud_tgt);
  estimateRigidTransformation(source_it, target_it, transformation_matrix);
}
 
template <typename PointSource, typename PointTarget, typename Scalar>
void
TransformationEstimation2D<PointSource, PointTarget, Scalar>::
    estimateRigidTransformation(const pcl::PointCloud<PointSource>& cloud_src,
                                const pcl::Indices& indices_src,
                                const pcl::PointCloud<PointTarget>& cloud_tgt,
                                Matrix4& transformation_matrix) const
{
  if (indices_src.size() != cloud_tgt.size()) {
    PCL_ERROR("[pcl::Transformation2D::estimateRigidTransformation] Number or points "
              "in source (%zu) differs than target (%zu)!\n",
              indices_src.size(),
              static_cast<std::size_t>(cloud_tgt.size()));
    return;
  }
 
  ConstCloudIterator<PointSource> source_it(cloud_src, indices_src);
  ConstCloudIterator<PointTarget> target_it(cloud_tgt);
  estimateRigidTransformation(source_it, target_it, transformation_matrix);
}
 
template <typename PointSource, typename PointTarget, typename Scalar>
inline void
TransformationEstimation2D<PointSource, PointTarget, Scalar>::
    estimateRigidTransformation(const pcl::PointCloud<PointSource>& cloud_src,
                                const pcl::Indices& indices_src,
                                const pcl::PointCloud<PointTarget>& cloud_tgt,
                                const pcl::Indices& indices_tgt,
                                Matrix4& transformation_matrix) const
{
  if (indices_src.size() != indices_tgt.size()) {
    PCL_ERROR("[pcl::TransformationEstimation2D::estimateRigidTransformation] Number "
              "or points in source (%lu) differs than target (%lu)!\n",
              indices_src.size(),
              indices_tgt.size());
    return;
  }
 
  ConstCloudIterator<PointSource> source_it(cloud_src, indices_src);
  ConstCloudIterator<PointTarget> target_it(cloud_tgt, indices_tgt);
  estimateRigidTransformation(source_it, target_it, transformation_matrix);
}
 
template <typename PointSource, typename PointTarget, typename Scalar>
void
TransformationEstimation2D<PointSource, PointTarget, Scalar>::
    estimateRigidTransformation(const pcl::PointCloud<PointSource>& cloud_src,
                                const pcl::PointCloud<PointTarget>& cloud_tgt,
                                const pcl::Correspondences& correspondences,
                                Matrix4& transformation_matrix) const
{
  ConstCloudIterator<PointSource> source_it(cloud_src, correspondences, true);
  ConstCloudIterator<PointTarget> target_it(cloud_tgt, correspondences, false);
  estimateRigidTransformation(source_it, target_it, transformation_matrix);
}
 
template <typename PointSource, typename PointTarget, typename Scalar>
inline void
TransformationEstimation2D<PointSource, PointTarget, Scalar>::
    estimateRigidTransformation(ConstCloudIterator<PointSource>& source_it,
                                ConstCloudIterator<PointTarget>& target_it,
                                Matrix4& transformation_matrix) const
{
  source_it.reset();
  target_it.reset();
 
  Eigen::Matrix<Scalar, 4, 1> centroid_src, centroid_tgt;
  // Estimate the centroids of source, target
  compute3DCentroid(source_it, centroid_src);
  compute3DCentroid(target_it, centroid_tgt);
  source_it.reset();
  target_it.reset();
 
  // ignore z component
  centroid_src[2] = 0.0f;
  centroid_tgt[2] = 0.0f;
  // Subtract the centroids from source, target
  Eigen::Matrix<Scalar, Eigen::Dynamic, Eigen::Dynamic> cloud_src_demean,
      cloud_tgt_demean;
  demeanPointCloud(source_it, centroid_src, cloud_src_demean);
  demeanPointCloud(target_it, centroid_tgt, cloud_tgt_demean);
 
  getTransformationFromCorrelation(cloud_src_demean,
                                   centroid_src,
                                   cloud_tgt_demean,
                                   centroid_tgt,
                                   transformation_matrix);
}
 
template <typename PointSource, typename PointTarget, typename Scalar>
void
TransformationEstimation2D<PointSource, PointTarget, Scalar>::
    getTransformationFromCorrelation(
        const Eigen::Matrix<Scalar, Eigen::Dynamic, Eigen::Dynamic>& cloud_src_demean,
        const Eigen::Matrix<Scalar, 4, 1>& centroid_src,
        const Eigen::Matrix<Scalar, Eigen::Dynamic, Eigen::Dynamic>& cloud_tgt_demean,
        const Eigen::Matrix<Scalar, 4, 1>& centroid_tgt,
        Matrix4& transformation_matrix) const
{
  transformation_matrix.setIdentity();
 
  // Assemble the correlation matrix H = source * target'
  Eigen::Matrix<Scalar, 3, 3> H =
      (cloud_src_demean * cloud_tgt_demean.transpose()).topLeftCorner(3, 3);
 
  float angle = std::atan2((H(0, 1) - H(1, 0)), (H(0, 0) + H(1, 1)));
 
  Eigen::Matrix<Scalar, 3, 3> R(Eigen::Matrix<Scalar, 3, 3>::Identity());
  R(0, 0) = R(1, 1) = std::cos(angle);
  R(0, 1) = -std::sin(angle);
  R(1, 0) = std::sin(angle);
 
  // Return the correct transformation
  transformation_matrix.topLeftCorner(3, 3).matrix() = R;
  const Eigen::Matrix<Scalar, 3, 1> Rc(R * centroid_src.head(3).matrix());
  transformation_matrix.block(0, 3, 3, 1).matrix() = centroid_tgt.head(3) - Rc;
}
 
} // namespace registration
} // namespace pcl
 
#endif // PCL_REGISTRATION_TRANSFORMATION_ESTIMATION_2D_HPP_