Add: filter to remove locally maximal points in the z dimension

filters/CMakeLists.txt

@@ -38,6 +38,7 @@ if(build)
 	    src/normal_refinement.cpp
         src/grid_minimum.cpp
         src/morphological_filter.cpp
+        src/local_maximum.cpp
         )
 
     set(incs
@@ -75,6 +76,7 @@ if(build)
         "include/pcl/${SUBSYS_NAME}/normal_refinement.h"
         "include/pcl/${SUBSYS_NAME}/grid_minimum.h"
         "include/pcl/${SUBSYS_NAME}/morphological_filter.h"
+        "include/pcl/${SUBSYS_NAME}/local_maximum.h"
         )
 
     set(impl_incs
@@ -109,6 +111,7 @@ if(build)
         "include/pcl/${SUBSYS_NAME}/impl/normal_refinement.hpp"
         "include/pcl/${SUBSYS_NAME}/impl/grid_minimum.hpp"
         "include/pcl/${SUBSYS_NAME}/impl/morphological_filter.hpp"
+        "include/pcl/${SUBSYS_NAME}/impl/local_maximum.hpp"
         )
 
     set(LIB_NAME "pcl_${SUBSYS_NAME}")

filters/include/pcl/filters/impl/local_maximum.hpp

@@ -0,0 +1,191 @@
+/*
+ * Software License Agreement (BSD License)
+ * 
+ *  Point Cloud Library (PCL) - www.pointclouds.org
+ *  Copyright (c) 2009-2012, Willow Garage, Inc.
+ *  Copyright (c) 2012-, Open Perception, Inc.
+ *  Copyright (c) 2014, RadiantBlue Technologies, 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.
+ *
+ * $Id$
+ *
+ */
+
+#ifndef PCL_FILTERS_IMPL_LOCAL_MAXIMUM_H_
+#define PCL_FILTERS_IMPL_LOCAL_MAXIMUM_H_
+
+#include <pcl/common/io.h>
+#include <pcl/filters/local_maximum.h>
+#include <pcl/filters/project_inliers.h>
+#include <pcl/ModelCoefficients.h>
+
+//////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+template <typename PointT> void
+pcl::LocalMaximum<PointT>::applyFilter (PointCloud &output)
+{
+  // Has the input dataset been set already?
+  if (!input_)
+  {
+    PCL_WARN ("[pcl::%s::applyFilter] No input dataset given!\n", getClassName ().c_str ());
+    output.width = output.height = 0;
+    output.points.clear ();
+    return;
+  }
+
+  std::vector<int> indices;
+
+  output.is_dense = true;
+  applyFilterIndices (indices);
+  pcl::copyPointCloud<PointT> (*input_, indices, output);
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+template <typename PointT> void
+pcl::LocalMaximum<PointT>::applyFilterIndices (std::vector<int> &indices)
+{
+  typename PointCloud::Ptr cloud_projected (new PointCloud);
+
+  // Create a set of planar coefficients with X=Y=0,Z=1
+  pcl::ModelCoefficients::Ptr coefficients (new pcl::ModelCoefficients ());
+  coefficients->values.resize (4);
+  coefficients->values[0] = coefficients->values[1] = 0;
+  coefficients->values[2] = 1.0;
+  coefficients->values[3] = 0;
+
+  // Create the filtering object and project input into xy plane
+  pcl::ProjectInliers<PointT> proj;
+  proj.setModelType (pcl::SACMODEL_PLANE);
+  proj.setInputCloud (input_);
+  proj.setModelCoefficients (coefficients);
+  proj.filter (*cloud_projected);
+
+  // Initialize the search class
+  if (!searcher_)
+  {
+    if (input_->isOrganized ())
+      searcher_.reset (new pcl::search::OrganizedNeighbor<PointT> ());
+    else
+      searcher_.reset (new pcl::search::KdTree<PointT> (false));
+  }
+  searcher_->setInputCloud (cloud_projected);
+
+  // The arrays to be used
+  indices.resize (indices_->size ());
+  removed_indices_->resize (indices_->size ());
+  int oii = 0, rii = 0;  // oii = output indices iterator, rii = removed indices iterator
+
+  std::vector<bool> point_is_max (false, indices_->size ());
+  std::vector<bool> point_is_visited (false, indices_->size ());
+
+  // Find all points within xy radius (i.e., a vertical cylinder) of the query
+  // point, removing those that are locally maximal (i.e., highest z within the
+  // cylinder)
+  for (int iii = 0; iii < static_cast<int> (indices_->size ()); ++iii)
+  {
+    if (!isFinite (input_->points[(*indices_)[iii]]))
+    {
+      continue;
+    }
+
+    // Points in the neighborhood of a previously identified local max, will
+    // not be maximal in their own neighborhood
+    if (point_is_visited[(*indices_)[iii]] && !point_is_max[(*indices_)[iii]])
+    {
+      continue;
+    }
+
+    // Assume the current query point is the maximum, mark as visited
+    point_is_max[(*indices_)[iii]] = true;
+    point_is_visited[(*indices_)[iii]] = true;
+
+    // Perform the radius search in the projected cloud
+    std::vector<int> radius_indices;
+    std::vector<float> radius_dists;
+    PointT p = cloud_projected->points[(*indices_)[iii]];
+    if (searcher_->radiusSearch (p, radius_, radius_indices, radius_dists) == 0)
+    {
+      PCL_WARN ("[pcl::%s::applyFilter] Searching for the closest %d neighbors failed.\n", getClassName ().c_str (), radius_);
+      continue;
+    }
+
+    // If query point is alone, we retain it regardless
+    if (radius_indices.size () == 1)
+    {
+        point_is_max[(*indices_)[iii]] = false;
+    }
+
+    // Check to see if a neighbor is higher than the query point
+    float query_z = input_->points[(*indices_)[iii]].z;
+    for (size_t k = 1; k < radius_indices.size (); ++k)  // k = 1 is the first neighbor
+    {
+      if (input_->points[radius_indices[k]].z > query_z)
+      {
+        // Query point is not the local max, no need to check others
+        point_is_max[(*indices_)[iii]] = false;
+        break;
+      }
+    }
+
+    // If the query point was a local max, all neighbors can be marked as
+    // visited, excluding them from future consideration as local maxima
+    if (point_is_max[(*indices_)[iii]])
+    {
+      for (size_t k = 1; k < radius_indices.size (); ++k)  // k = 1 is the first neighbor
+      {
+        point_is_visited[radius_indices[k]] = true;
+      }
+    }
+
+    // Points that are local maxima are passed to removed indices
+    // Unless negative was set, then it's the opposite condition
+    if ((!negative_ && point_is_max[(*indices_)[iii]]) || (negative_ && !point_is_max[(*indices_)[iii]]))
+    {
+      if (extract_removed_indices_)
+      {
+        (*removed_indices_)[rii++] = (*indices_)[iii];
+      }
+
+      continue;
+    }
+
+    // Otherwise it was a normal point for output (inlier)
+    indices[oii++] = (*indices_)[iii];
+  }
+
+  // Resize the output arrays
+  indices.resize (oii);
+  removed_indices_->resize (rii);
+}
+
+#define PCL_INSTANTIATE_LocalMaximum(T) template class PCL_EXPORTS pcl::LocalMaximum<T>;
+
+#endif    // PCL_FILTERS_IMPL_LOCAL_MAXIMUM_H_
+

filters/include/pcl/filters/local_maximum.h

@@ -0,0 +1,133 @@
+/*
+ * Software License Agreement (BSD License)
+ *
+ *  Point Cloud Library (PCL) - www.pointclouds.org
+ *  Copyright (c) 2009-2012, Willow Garage, Inc.
+ *  Copyright (c) 2012-, Open Perception, Inc.
+ *  Copyright (c) 2014, RadiantBlue Technologies, 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.
+ *
+ * $Id$
+ *
+ */
+
+#ifndef PCL_FILTERS_LOCAL_MAXIMUM_H_
+#define PCL_FILTERS_LOCAL_MAXIMUM_H_
+
+#include <pcl/filters/filter_indices.h>
+#include <pcl/search/pcl_search.h>
+
+namespace pcl
+{
+  /** \brief LocalMaximum downsamples the cloud, by eliminating points that are locally maximal.
+    *
+    * The LocalMaximum class analyzes each point and removes those that are
+    * found to be locally maximal with respect to their neighbors (found via
+    * radius search). The comparison is made in the z dimension only at this
+    * time.
+    *
+    * \author Bradley J Chambers
+    * \ingroup filters
+    */
+  template <typename PointT>
+  class LocalMaximum: public FilterIndices<PointT>
+  {
+    protected:
+      typedef typename FilterIndices<PointT>::PointCloud PointCloud;
+      typedef typename pcl::search::Search<PointT>::Ptr SearcherPtr;
+
+    public:
+      /** \brief Empty constructor. */
+      LocalMaximum (bool extract_removed_indices = false) :
+        FilterIndices<PointT>::FilterIndices (extract_removed_indices),
+        searcher_ (),
+        radius_ (1)
+      {
+        filter_name_ = "LocalMaximum";
+      }
+
+      /** \brief Set the radius to use to determine if a point is the local max.
+        * \param[in] radius The radius to use to determine if a point is the local max.
+        */
+      inline void
+      setRadius (float radius) { radius_ = radius; }
+
+      /** \brief Get the radius to use to determine if a point is the local max.
+        * \param[in] radius The radius to use to determine if a point is the local max.
+        */
+      inline float
+      getRadius () const { return (radius_); }
+
+    protected:
+      using PCLBase<PointT>::input_;
+      using PCLBase<PointT>::indices_;
+      using Filter<PointT>::filter_name_;
+      using Filter<PointT>::getClassName;
+      using FilterIndices<PointT>::negative_;
+      using FilterIndices<PointT>::extract_removed_indices_;
+      using FilterIndices<PointT>::removed_indices_;
+
+      /** \brief Downsample a Point Cloud by eliminating points that are locally maximal in z
+        * \param[out] output the resultant point cloud message
+        */
+      void
+      applyFilter (PointCloud &output);
+
+      /** \brief Filtered results are indexed by an indices array.
+        * \param[out] indices The resultant indices.
+        */
+      void
+      applyFilter (std::vector<int> &indices)
+      {
+        applyFilterIndices (indices);
+      }
+
+      /** \brief Filtered results are indexed by an indices array.
+        * \param[out] indices The resultant indices.
+        */
+      void
+      applyFilterIndices (std::vector<int> &indices);
+
+    private:
+      /** \brief A pointer to the spatial search object. */
+      SearcherPtr searcher_;
+
+      /** \brief The radius to use to determine if a point is the local max. */
+      float radius_;
+  };
+}
+
+#ifdef PCL_NO_PRECOMPILE
+#include <pcl/filters/impl/local_maximum.hpp>
+#endif
+
+#endif  //#ifndef PCL_FILTERS_LOCAL_MAXIMUM_H_
+