Point Cloud Library (PCL)  1.14.0-dev
uniform_sampling.h
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39 
40 #pragma once
41 
42 #include <pcl/filters/filter.h>
43 
44 #include <unordered_map>
45 
46 namespace pcl
47 {
48  /** \brief @b UniformSampling assembles a local 3D grid over a given PointCloud, and downsamples + filters the data.
49  *
50  * The @b UniformSampling class creates a *3D voxel grid* (think about a voxel
51  * grid as a set of tiny 3D boxes in space) over the input point cloud data.
52  * Then, in each *voxel* (i.e., 3D box), all the points present will be
53  * approximated (i.e., *downsampled*) with the closest point to the center of the voxel.
54  *
55  * \author Radu Bogdan Rusu
56  * \ingroup filters
57  */
58  template <typename PointT>
59  class UniformSampling: public Filter<PointT>
60  {
61  using PointCloud = typename Filter<PointT>::PointCloud;
62 
69 
70  public:
71  using Ptr = shared_ptr<UniformSampling<PointT> >;
72  using ConstPtr = shared_ptr<const UniformSampling<PointT> >;
73 
75 
76  /** \brief Empty constructor. */
77  UniformSampling (bool extract_removed_indices = false) :
78  Filter<PointT>(extract_removed_indices),
79  leaves_ (),
80  leaf_size_ (Eigen::Vector4f::Zero ()),
81  inverse_leaf_size_ (Eigen::Vector4f::Zero ()),
82  min_b_ (Eigen::Vector4i::Zero ()),
83  max_b_ (Eigen::Vector4i::Zero ()),
84  div_b_ (Eigen::Vector4i::Zero ()),
85  divb_mul_ (Eigen::Vector4i::Zero ())
86  {
87  filter_name_ = "UniformSampling";
88  }
89 
90  /** \brief Destructor. */
91  ~UniformSampling () override
92  {
93  leaves_.clear();
94  }
95 
96  /** \brief Set the 3D grid leaf size.
97  * \param radius the 3D grid leaf size
98  */
99  virtual inline void
100  setRadiusSearch (double radius)
101  {
102  leaf_size_[0] = leaf_size_[1] = leaf_size_[2] = static_cast<float> (radius);
103  // Avoid division errors
104  if (leaf_size_[3] == 0)
105  leaf_size_[3] = 1;
106  // Use multiplications instead of divisions
107  inverse_leaf_size_ = Eigen::Array4f::Ones () / leaf_size_.array ();
108  search_radius_ = radius;
109  }
110 
111  protected:
112  /** \brief Simple structure to hold an nD centroid and the number of points in a leaf. */
113  struct Leaf
114  {
115  Leaf () = default;
116  int idx{-1};
117  };
118 
119  /** \brief The 3D grid leaves. */
120  std::unordered_map<std::size_t, Leaf> leaves_;
121 
122  /** \brief The size of a leaf. */
123  Eigen::Vector4f leaf_size_;
124 
125  /** \brief Internal leaf sizes stored as 1/leaf_size_ for efficiency reasons. */
126  Eigen::Array4f inverse_leaf_size_;
127 
128  /** \brief The minimum and maximum bin coordinates, the number of divisions, and the division multiplier. */
129  Eigen::Vector4i min_b_, max_b_, div_b_, divb_mul_;
130 
131  /** \brief The nearest neighbors search radius for each point. */
132  double search_radius_{0.0};
133 
134  /** \brief Downsample a Point Cloud using a voxelized grid approach
135  * \param[out] output the resultant point cloud message
136  */
137  void
138  applyFilter (PointCloud &output) override;
139  };
140 }
141 
142 #ifdef PCL_NO_PRECOMPILE
143 #include <pcl/filters/impl/uniform_sampling.hpp>
144 #endif
Filter represents the base filter class.
Definition: filter.h:81
shared_ptr< Filter< PointT > > Ptr
Definition: filter.h:83
shared_ptr< const Filter< PointT > > ConstPtr
Definition: filter.h:84
std::string filter_name_
The filter name.
Definition: filter.h:158
PointCloud represents the base class in PCL for storing collections of 3D points.
Definition: point_cloud.h:173
UniformSampling assembles a local 3D grid over a given PointCloud, and downsamples + filters the data...
Eigen::Vector4i min_b_
The minimum and maximum bin coordinates, the number of divisions, and the division multiplier.
~UniformSampling() override
Destructor.
Eigen::Vector4f leaf_size_
The size of a leaf.
Eigen::Array4f inverse_leaf_size_
Internal leaf sizes stored as 1/leaf_size_ for efficiency reasons.
PCL_MAKE_ALIGNED_OPERATOR_NEW UniformSampling(bool extract_removed_indices=false)
Empty constructor.
double search_radius_
The nearest neighbors search radius for each point.
std::unordered_map< std::size_t, Leaf > leaves_
The 3D grid leaves.
Eigen::Vector4i divb_mul_
virtual void setRadiusSearch(double radius)
Set the 3D grid leaf size.
void applyFilter(PointCloud &output) override
Downsample a Point Cloud using a voxelized grid approach.
Eigen::Vector4i div_b_
Eigen::Vector4i max_b_
#define PCL_MAKE_ALIGNED_OPERATOR_NEW
Macro to signal a class requires a custom allocator.
Definition: memory.h:63
Definition: bfgs.h:10
A point structure representing Euclidean xyz coordinates, and the RGB color.
Simple structure to hold an nD centroid and the number of points in a leaf.