Point Cloud Library (PCL)  1.8.1-dev
uniform_sampling.h
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39
40 #ifndef PCL_FILTERS_UNIFORM_SAMPLING_H_
41 #define PCL_FILTERS_UNIFORM_SAMPLING_H_
42
43 #include <pcl/filters/filter.h>
44 #include <boost/unordered_map.hpp>
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 their centroid. This approach is
54  * a bit slower than approximating them with the center of the voxel, but it
55  * represents the underlying surface more accurately.
56  *
57  * \author Radu Bogdan Rusu
58  * \ingroup keypoints
59  */
60  template <typename PointT>
61  class UniformSampling: public Filter<PointT>
62  {
63  typedef typename Filter<PointT>::PointCloud PointCloud;
64
69
70  public:
71  typedef boost::shared_ptr<UniformSampling<PointT> > Ptr;
72  typedef boost::shared_ptr<const UniformSampling<PointT> > ConstPtr;
73
74  /** \brief Empty constructor. */
75  UniformSampling (bool extract_removed_indices = false) :
76  Filter<PointT>(extract_removed_indices),
77  leaves_ (),
78  leaf_size_ (Eigen::Vector4f::Zero ()),
79  inverse_leaf_size_ (Eigen::Vector4f::Zero ()),
80  min_b_ (Eigen::Vector4i::Zero ()),
81  max_b_ (Eigen::Vector4i::Zero ()),
82  div_b_ (Eigen::Vector4i::Zero ()),
83  divb_mul_ (Eigen::Vector4i::Zero ()),
85  {
86  filter_name_ = "UniformSampling";
87  }
88
89  /** \brief Destructor. */
90  virtual ~UniformSampling ()
91  {
92  leaves_.clear();
93  }
94
95  /** \brief Set the 3D grid leaf size.
96  * \param radius the 3D grid leaf size
97  */
98  virtual inline void
100  {
101  leaf_size_[0] = leaf_size_[1] = leaf_size_[2] = static_cast<float> (radius);
102  // Avoid division errors
103  if (leaf_size_[3] == 0)
104  leaf_size_[3] = 1;
105  // Use multiplications instead of divisions
106  inverse_leaf_size_ = Eigen::Array4f::Ones () / leaf_size_.array ();
108  }
109
110  protected:
111  /** \brief Simple structure to hold an nD centroid and the number of points in a leaf. */
112  struct Leaf
113  {
114  Leaf () : idx (-1) { }
115  int idx;
116  };
117
118  /** \brief The 3D grid leaves. */
119  boost::unordered_map<size_t, Leaf> leaves_;
120
121  /** \brief The size of a leaf. */
122  Eigen::Vector4f leaf_size_;
123
124  /** \brief Internal leaf sizes stored as 1/leaf_size_ for efficiency reasons. */
125  Eigen::Array4f inverse_leaf_size_;
126
127  /** \brief The minimum and maximum bin coordinates, the number of divisions, and the division multiplier. */
128  Eigen::Vector4i min_b_, max_b_, div_b_, divb_mul_;
129
130  /** \brief The nearest neighbors search radius for each point. */
132
133  /** \brief Downsample a Point Cloud using a voxelized grid approach
134  * \param[out] output the resultant point cloud message
135  */
136  void
137  applyFilter (PointCloud &output);
138  };
139 }
140
141 #ifdef PCL_NO_PRECOMPILE
142 #include <pcl/filters/impl/uniform_sampling.hpp>
143 #endif
144
145 #endif //#ifndef PCL_FILTERS_UNIFORM_SAMPLING_H_
146
Eigen::Vector4i max_b_
Eigen::Vector4i divb_mul_
Eigen::Vector4f leaf_size_
The size of a leaf.
boost::shared_ptr< const UniformSampling< PointT > > ConstPtr
boost::unordered_map< size_t, Leaf > leaves_
The 3D grid leaves.
virtual ~UniformSampling()
Destructor.
The nearest neighbors search radius for each point.
Eigen::Vector4i div_b_
UniformSampling(bool extract_removed_indices=false)
Empty constructor.
Filter represents the base filter class.
Definition: filter.h:84
Eigen::Vector4i min_b_
The minimum and maximum bin coordinates, the number of divisions, and the division multiplier...
boost::shared_ptr< UniformSampling< PointT > > Ptr
void applyFilter(PointCloud &output)
Downsample a Point Cloud using a voxelized grid approach.
std::string filter_name_
The filter name.
Definition: filter.h:166
A point structure representing Euclidean xyz coordinates, and the RGB color.