median_filter.h

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#pragma once
 
#include <pcl/filters/filter.h>
 
namespace pcl
{
  /** \brief Implementation of the median filter.
    * The median filter is one of the simplest and wide-spread image processing filters. It is known to perform well
    * with "shot"/impulse noise (some individual pixels having extreme values), it does not reduce contrast across steps
    * in the function (as compared to filters based on averaging), and it is robust to outliers. Furthermore, it is
    * simple to implement and efficient, as it requires a single pass over the image. It consists of a moving window of
    * fixed size that replaces the pixel in the center with the median inside the window.
    *
    * \note This algorithm filters only the depth (z-component) of _organized_ and untransformed (i.e., in camera coordinates)
    * point clouds. An error will be outputted if an unorganized cloud is given to the class instance.
    *
    * \author Alexandru E. Ichim
    * \ingroup filters
    */
  template <typename PointT>
  class MedianFilter : public pcl::Filter<PointT>
  {
      using pcl::Filter<PointT>::input_;
      using PointCloud = typename pcl::Filter<PointT>::PointCloud;
 
    public:
      /** \brief Empty constructor. */
      MedianFilter () = default;
 
      /** \brief Set the window size of the filter.
        * \param[in] window_size the new window size
        */
      inline void
      setWindowSize (int window_size)
      { window_size_ = window_size; }
 
      /** \brief Get the window size of the filter.
        * \returns the window size of the filter
        */
      inline int
      getWindowSize () const
      { return window_size_; }
 
      /** \brief Set the largest value one dexel is allowed to move
        * \param[in] max_allowed_movement maximum value a dexel is allowed to move during filtering
        */
      inline void
      setMaxAllowedMovement (float max_allowed_movement)
      { max_allowed_movement_ = max_allowed_movement; }
 
      /** \brief Get the maximum distance one point is allowed to move along the z-axis.
        * \returns the maximum distance a dexel is allowed to move
        */
      inline float
      getMaxAllowedMovement () const
      { return max_allowed_movement_; }
 
      /** \brief Filter the input data and store the results into output.
        * \param[out] output the result point cloud
        */
      void
      applyFilter (PointCloud &output) override;
 
    protected:
      int window_size_{5};
      float max_allowed_movement_{std::numeric_limits<float>::max ()};
  };
}
 
#ifdef PCL_NO_PRECOMPILE
#include <pcl/filters/impl/median_filter.hpp>
#else
#define PCL_INSTANTIATE_MedianFilter(T) template class PCL_EXPORTS pcl::MedianFilter<T>;
#endif