COccupancyGridMapFeatureExtractor.h

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          http://www.mrpt.org/                          |
   |                                                                        |
   | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file     |
   | See: http://www.mrpt.org/Authors - All rights reserved.                |
   | Released under BSD License. See details in http://www.mrpt.org/License |
   +------------------------------------------------------------------------+ */
#ifndef COccupancyGridMapFeatureExtractor_H
#define COccupancyGridMapFeatureExtractor_H

#include <mrpt/maps/COccupancyGridMap2D.h>
#include <mrpt/maps/CLandmarksMap.h>
#include <mrpt/vision/CFeatureExtraction.h>

#include <mrpt/utils/CObserver.h>

namespace mrpt
{
namespace slam
{
/**  A class for detecting features from occupancy grid maps.
  *   The main method is "COccupancyGridMapFeatureExtractor::extractFeatures()",
 * which makes use
  *    of an advanced cache mechanism to avoid redoing work when applied several
 * times on the same
  *    occupancy grid maps (unless they changed in the meanwhile).
  *
  *  For an uncached version (which is a static method that can be called
 * without instantiating COccupancyGridMapFeatureExtractor)
  *  see COccupancyGridMapFeatureExtractor::uncached_extractFeatures()
  *
  * \ingroup mrpt_slam_grp
  */
class COccupancyGridMapFeatureExtractor : public mrpt::utils::CObserver
{
   public:
        /** Default ctor */
        COccupancyGridMapFeatureExtractor();
        /** Destructor */
        ~COccupancyGridMapFeatureExtractor();

        /** Computes a set of distinctive landmarks from an occupancy grid, and
         * store them (previous content is not erased!) into the given landmarks
         * map.
          *   Landmarks type can be any declared in
         * mrpt::vision::CFeatureExtraction::TOptions
          *
          * \note See the paper "..."
          * \sa uncached_extractFeatures
          */
        void extractFeatures(
                const mrpt::maps::COccupancyGridMap2D& grid,
                mrpt::maps::CLandmarksMap& outMap, const size_t number_of_features,
                const mrpt::vision::TDescriptorType descriptors,
                const mrpt::vision::CFeatureExtraction::TOptions& feat_options);

        /** Computes a set of distinctive landmarks from an occupancy grid, and
         * store them (previous content is not erased!) into the given landmarks
         * map.
          *   Landmarks type can be any declared in
         * mrpt::vision::CFeatureExtraction::TOptions
          *
          * \note See the paper "..."
          * \sa uncached_extractFeatures
          */
        static void uncached_extractFeatures(
                const mrpt::maps::COccupancyGridMap2D& grid,
                mrpt::maps::CLandmarksMap& outMap, const size_t number_of_features,
                const mrpt::vision::TDescriptorType descriptors,
                const mrpt::vision::CFeatureExtraction::TOptions& feat_options);

   protected:
        /** This will receive the events from maps in order to purge the cache. */
        void OnEvent(const mrpt::utils::mrptEvent& e);
        typedef std::map<const mrpt::maps::COccupancyGridMap2D*,
                                         mrpt::maps::CLandmarksMap::Ptr>
                TCache;
        /** A cache of already computed maps. */
        TCache m_cache;

};  // End of class def.

}  // End of namespace
}  // End of namespace

#endif