vpCannyEdgeDetection.h

/*
 * ViSP, open source Visual Servoing Platform software.
 * Copyright (C) 2005 - 2023 by Inria. All rights reserved.
 *
 * This software is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * See the file LICENSE.txt at the root directory of this source
 * distribution for additional information about the GNU GPL.
 *
 * For using ViSP with software that can not be combined with the GNU
 * GPL, please contact Inria about acquiring a ViSP Professional
 * Edition License.
 *
 * See https://visp.inria.fr for more information.
 *
 * This software was developed at:
 * Inria Rennes - Bretagne Atlantique
 * Campus Universitaire de Beaulieu
 * 35042 Rennes Cedex
 * France
 *
 * If you have questions regarding the use of this file, please contact
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 *
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */
 
#ifndef _vpCannyEdgeDetection_h_
#define _vpCannyEdgeDetection_h_
 
// System includes
#include <map>
#include <vector>
 
// ViSP include
#include <visp3/core/vpConfig.h>
#include <visp3/core/vpImage.h>
#include <visp3/core/vpImageFilter.h>
 
// 3rd parties include
#ifdef VISP_HAVE_NLOHMANN_JSON
#include <nlohmann/json.hpp>
#endif
 
class VISP_EXPORT vpCannyEdgeDetection
{
private:
  typedef enum EdgeType
  {
    STRONG_EDGE, 
    WEAK_EDGE,
    ON_CHECK 
  } EdgeType;
 
  // Filtering + gradient methods choice
  vpImageFilter::vpCannyFilteringAndGradientType m_filteringAndGradientType; 
  // // Gaussian smoothing attributes
  int m_gaussianKernelSize; 
  float m_gaussianStdev;   
  vpArray2D<float> m_fg; 
  // // Gradient computation attributes
  bool m_areGradientAvailable; 
  unsigned int m_gradientFilterKernelSize; 
  vpArray2D<float> m_gradientFilterX; 
  vpArray2D<float> m_gradientFilterY; 
  vpImage<float> m_dIx; 
  vpImage<float> m_dIy; 
  // // Edge thining attributes
  std::map<std::pair<unsigned int, unsigned int>, float> m_edgeCandidateAndGradient; 
  // // Hysteresis thresholding attributes
  float m_lowerThreshold; 
  float m_lowerThresholdRatio; 
  float m_upperThreshold; 
  float m_upperThresholdRatio; 
  // // Edge tracking attributes
  std::map<std::pair<unsigned int, unsigned int>, EdgeType> m_edgePointsCandidates; 
  vpImage<unsigned char> m_edgeMap; 
  const vpImage<bool> *mp_mask; 
  void initGaussianFilters();
 
  void initGradientFilters();
 
  void performFilteringAndGradientComputation(const vpImage<unsigned char> &I);
 
  void performEdgeThinning(const float &lowerThreshold);
 
  void performHysteresisThresholding(const float &lowerThreshold, const float &upperThreshold);
 
  bool recursiveSearchForStrongEdge(const std::pair<unsigned int, unsigned int> &coordinates);
 
  void performEdgeTracking();
 
public:
  vpCannyEdgeDetection();
 
  vpCannyEdgeDetection(const int &gaussianKernelSize, const float &gaussianStdev, const unsigned int &sobelAperture,
                       const float &lowerThreshold = -1.f, const float &upperThreshold = -1.f,
                       const float &lowerThresholdRatio = 0.6f, const float &upperThresholdRatio = 0.8f,
                       const vpImageFilter::vpCannyFilteringAndGradientType &filteringType = vpImageFilter::CANNY_GBLUR_SOBEL_FILTERING);
 
  // // Configuration from files
#ifdef VISP_HAVE_NLOHMANN_JSON
  vpCannyEdgeDetection(const std::string &jsonPath);
 
  void initFromJSON(const std::string &jsonPath);
 
  friend inline void from_json(const nlohmann::json &j, vpCannyEdgeDetection &detector)
  {
    std::string filteringAndGradientName = vpImageFilter::vpCannyFilteringAndGradientTypeToString(detector.m_filteringAndGradientType);
    filteringAndGradientName = j.value("filteringAndGradientType", filteringAndGradientName);
    detector.m_filteringAndGradientType = vpImageFilter::vpCannyFilteringAndGradientTypeFromString(filteringAndGradientName);
    detector.m_gaussianKernelSize = j.value("gaussianSize", detector.m_gaussianKernelSize);
    detector.m_gaussianStdev = j.value("gaussianStdev", detector.m_gaussianStdev);
    detector.m_lowerThreshold = j.value("lowerThreshold", detector.m_lowerThreshold);
    detector.m_lowerThresholdRatio = j.value("lowerThresholdRatio", detector.m_lowerThresholdRatio);
    detector.m_gradientFilterKernelSize = j.value("gradientFilterKernelSize", detector.m_gradientFilterKernelSize);
    detector.m_upperThreshold = j.value("upperThreshold", detector.m_upperThreshold);
    detector.m_upperThresholdRatio = j.value("upperThresholdRatio", detector.m_upperThresholdRatio);
  }
 
  friend inline void to_json(nlohmann::json &j, const vpCannyEdgeDetection &detector)
  {
    std::string filteringAndGradientName = vpImageFilter::vpCannyFilteringAndGradientTypeToString(detector.m_filteringAndGradientType);
    j = nlohmann::json {
            {"filteringAndGradientType", filteringAndGradientName},
            {"gaussianSize", detector.m_gaussianKernelSize},
            {"gaussianStdev", detector.m_gaussianStdev},
            {"lowerThreshold", detector.m_lowerThreshold},
            {"lowerThresholdRatio", detector.m_lowerThresholdRatio},
            {"gradientFilterKernelSize", detector.m_gradientFilterKernelSize},
            {"upperThreshold", detector.m_upperThreshold},
            {"upperThresholdRatio", detector.m_upperThresholdRatio}
    };
  }
#endif
 
#ifdef HAVE_OPENCV_CORE
  vpImage<unsigned char> detect(const cv::Mat &cv_I);
#endif
 
  vpImage<unsigned char> detect(const vpImage<vpRGBa> &I_color);
 
  vpImage<unsigned char> detect(const vpImage<unsigned char> &I);
 
  inline void setFilteringAndGradientType(const vpImageFilter::vpCannyFilteringAndGradientType &type)
  {
    m_filteringAndGradientType = type;
    initGradientFilters();
  }
 
  inline void setGradients(const vpImage<float> &dIx, const vpImage<float> &dIy)
  {
    m_dIx = dIx;
    m_dIy = dIy;
    m_areGradientAvailable = true;
  }
 
  inline void setCannyThresholds(const float &lowerThresh, const float &upperThresh)
  {
    m_lowerThreshold = lowerThresh;
    m_upperThreshold = upperThresh;
  }
 
  inline void setCannyThresholdsRatio(const float &lowerThreshRatio, const float &upperThreshRatio)
  {
    m_lowerThresholdRatio = lowerThreshRatio;
    m_upperThresholdRatio = upperThreshRatio;
  }
 
  inline void setGaussianFilterParameters(const int &kernelSize, const float &stdev)
  {
    m_gaussianKernelSize = kernelSize;
    m_gaussianStdev = stdev;
    initGaussianFilters();
  }
 
  inline void setGradientFilterAperture(const unsigned int &apertureSize)
  {
    m_gradientFilterKernelSize = apertureSize;
    initGradientFilters();
  }
 
  inline void setMask(const vpImage<bool> *p_mask)
  {
    mp_mask = p_mask;
  }
};
#endif