denoise_layer.hpp

// Copyright (c) 2023 Andrey Ryzhikov
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
 
#ifndef NAV2_COSTMAP_2D__DENOISE_LAYER_HPP_
#define NAV2_COSTMAP_2D__DENOISE_LAYER_HPP_
 
#include "nav2_costmap_2d/layer.hpp"
#include "nav2_costmap_2d/denoise/image_processing.hpp"
 
namespace nav2_costmap_2d
{
class DenoiseLayer : public Layer
{
  friend class DenoiseLayerTester;  // For test some private methods using gtest
 
public:
  DenoiseLayer() = default;
  ~DenoiseLayer() = default;
 
  void reset() override;
 
  bool isClearable() override;
 
  void updateBounds(
    double robot_x, double robot_y, double robot_yaw,
    double * min_x, double * min_y,
    double * max_x, double * max_y) override;
 
  void updateCosts(
    nav2_costmap_2d::Costmap2D & master_grid,
    int min_x, int min_y, int max_x, int max_y) override;
 
protected:
  void onInitialize() override;
 
private:
  void denoise(Image<uint8_t> & image) const;
 
  void removeGroups(Image<uint8_t> & image) const;
 
  void removeSinglePixels(Image<uint8_t> & image) const;
  bool isBackground(uint8_t pixel) const;
 
private:
  // The border value of group size. Groups of this and larger size will be kept
  size_t minimal_group_size_{};
  // Pixels connectivity type. Determines how pixels belonging to the same group can be arranged
  ConnectivityType group_connectivity_type_{ConnectivityType::Way8};
  // Memory buffer for temporal image
  mutable MemoryBuffer buffer_;
  // Implementing the removal of grouped noise
  imgproc_impl::GroupsRemover groups_remover_;
  // Interpret NO_INFORMATION code as obstacle
  bool no_information_is_obstacle_{};
};
 
}  // namespace nav2_costmap_2d
 
#endif  // NAV2_COSTMAP_2D__DENOISE_LAYER_HPP_