text: /*
   * Copyright (C) 2005-2019 Centre National d'Etudes Spatiales (CNES)
   *
   * This file is part of Orfeo Toolbox
   *
   *     https://www.orfeo-toolbox.org/
   *
   * 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 otbPathListToHistogramGenerator_h
  #define otbPathListToHistogramGenerator_h
  
  #include "itkSampleToHistogramFilter.h"
  #include "itkHistogram.h"
  #include "itkListSample.h"
  #include "itkVector.h"
  #include "otbObjectList.h"
  
  //TODO : write a HistogramSource when outputting Histogram
  
  namespace otb
  {
  
  /** \class PathListToHistogramGenerator
   *  \brief This class generates an histogram from a list of path.
   *
   *  The concept of Histogram in ITK is quite generic. It has been designed to
   *  manage multiple components data. This class facilitates the computation of
   *  an histogram from a list of path. Internally it creates a List that is feed into
   *  the ListSampleToHistogramGenerator.
   *
   *
   * \ingroup OTBPath
   */
  
  template<class TPath, class TFunction>
  class PathListToHistogramGenerator : public itk::ProcessObject
  {
  public:
    /** Standard typedefs */
    typedef PathListToHistogramGenerator  Self;
    typedef itk::ProcessObject            Superclass;
    typedef itk::SmartPointer<Self>       Pointer;
    typedef itk::SmartPointer<const Self> ConstPointer;
  
    /** Run-time type information (and related methods). */
    itkTypeMacro(PathListToHistogramGenerator, itk::ProcessObject);
  
    /** standard New() method support */
    itkNewMacro(Self);
  
    typedef TPath                         PathType;
    typedef typename PathType::Pointer    PathPointer;
    typedef ObjectList<PathType>          PathListType;
  
    typedef TFunction                     FunctionType;
  
    typedef typename TFunction::OutputType RealType;
  
    typedef RealType                                          MeasurementType;
    typedef itk::Vector<MeasurementType, 1>                   ListSampleVectorType;
    typedef itk::Statistics::ListSample<ListSampleVectorType> ListSampleType;
    typedef typename ListSampleType::Pointer                  ListSamplePointer;
    typedef typename ListSampleType::ConstPointer             ListSampleConstPointer;
  
    typedef itk::Statistics::DenseFrequencyContainer2         FrequencyContainerType;
    typedef itk::Statistics::Histogram< MeasurementType,
              FrequencyContainerType >                        HistogramType;
  
    typedef itk::Statistics::SampleToHistogramFilter<
        ListSampleType,
        HistogramType>                                    GeneratorType;
    typedef typename GeneratorType::Pointer               GeneratorPointer;
  
    typedef typename HistogramType::Pointer               HistogramPointer;
    typedef typename HistogramType::ConstPointer          HistogramConstPointer;
    typedef typename HistogramType::SizeType              SizeType;
    typedef typename HistogramType::MeasurementVectorType MeasurementVectorType;
  
    /** DataObject typedef*/
    typedef typename Superclass::DataObjectPointer        DataObjectPointer;
    typedef itk::ProcessObject::DataObjectPointerArraySizeType DataObjectPointerArraySizeType;
  
    void GraftNthOutput(unsigned int idx, itk::DataObject *graft);
    void GraftOutput(itk::DataObject *graft);
  
  public:
  
    /** Connects the input PathList for which the histogram is going to be computed */
    using Superclass::SetInput;
    void SetInput(const PathListType* path);
    const PathListType* GetInput() const;
  
    // Return the output histogram.
     const HistogramType * GetOutput() const;
  
    /** Set number of histogram bins */
    void SetNumberOfBins(const SizeType& size);
  
    /** Set marginal scale value to be passed to the histogram generator */
    void SetMarginalScale(double marginalScale);
    void SetHistogramMin(const MeasurementVectorType& histogramMin);
    void SetHistogramMax(const MeasurementVectorType& histogramMax);
    void SetAutoMinMax(bool autoMinMax);
  
  protected:
    PathListToHistogramGenerator();
    ~PathListToHistogramGenerator() override {}
    void GenerateData() override;
    DataObjectPointer MakeOutput(DataObjectPointerArraySizeType) override;
    using Superclass::MakeOutput;
  
    void PrintSelf(std::ostream& os, itk::Indent indent) const override;
  
  private:
  
    GeneratorPointer m_HistogramGenerator;
  
  };
  
  } // end of namespace OTB
  
  #ifndef OTB_MANUAL_INSTANTIATION
  #include "otbPathListToHistogramGenerator.hxx"
  #endif
  
  #endif
  