text: /*
   * Copyright (C) 1999-2011 Insight Software Consortium
   * 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 otbStreamingHistogramVectorImageFilter_h
  #define otbStreamingHistogramVectorImageFilter_h
  
  #include "otbPersistentImageFilter.h"
  #include "otbPersistentFilterStreamingDecorator.h"
  
  #include "otbObjectList.h"
  #include "itkStatisticsAlgorithm.h"
  #include "itkNumericTraits.h"
  #include "itkHistogram.h"
  
  namespace otb
  {
  
  /** \class PersistentHistogramVectorImageFilter
   * \brief Compute the histogram of a large image using streaming
   *
   *  This filter persists its temporary data. It means that if you Update it n times on n different
   * requested regions, the output histogram will be the histogram of the whole set of n regions.
   *
   * To reset the temporary data, one should call the Reset() function.
   *
   * To get the histogram once the regions have been processed via the pipeline, use the Synthetize() method.
   *
   * \sa PersistentImageFilter
   * \ingroup Streamed
   * \ingroup Multithreaded
   * \ingroup MathematicalStatisticsImageFilters
   *
   *
   * \ingroup OTBStatistics
   */
  template<class TInputImage>
  class ITK_EXPORT PersistentHistogramVectorImageFilter :
    public PersistentImageFilter<TInputImage, TInputImage>
  {
  public:
    /** Standard Self typedef */
    typedef PersistentHistogramVectorImageFilter               Self;
    typedef PersistentImageFilter<TInputImage, TInputImage> Superclass;
    typedef itk::SmartPointer<Self>                         Pointer;
    typedef itk::SmartPointer<const Self>                   ConstPointer;
  
    /** Method for creation through the object factory. */
    itkNewMacro(Self);
  
    /** Runtime information support. */
    itkTypeMacro(PersistentHistogramVectorImageFilter, PersistentImageFilter);
  
    /** Image related typedefs. */
    typedef TInputImage                             ImageType;
    typedef typename TInputImage::Pointer           InputImagePointer;
    typedef typename TInputImage::RegionType        RegionType;
    typedef typename TInputImage::SizeType          SizeType;
    typedef typename TInputImage::IndexType         IndexType;
    typedef typename TInputImage::PixelType         PixelType;
    typedef typename TInputImage::InternalPixelType InternalPixelType;
  
    itkStaticConstMacro(InputImageDimension, unsigned int, TInputImage::ImageDimension);
  
    /** Image related typedefs. */
    itkStaticConstMacro(ImageDimension, unsigned int, TInputImage::ImageDimension);
  
    /** Type to use for computations. */
    typedef typename itk::NumericTraits<InternalPixelType>::RealType RealType;
    typedef itk::VariableLengthVector<RealType>                      RealPixelType;
  
    /** Smart Pointer type to a DataObject. */
    typedef typename itk::DataObject::Pointer       DataObjectPointer;
    typedef itk::ProcessObject::DataObjectPointerArraySizeType DataObjectPointerArraySizeType;
  
    /** Types for histogram */
    typedef itk::Statistics::DenseFrequencyContainer2        DFContainerType;
  
    typedef
      typename itk::NumericTraits<InternalPixelType>::RealType
      HistogramMeasurementRealType;
  
    typedef
      itk::Statistics::Histogram<HistogramMeasurementRealType, DFContainerType>
      HistogramType;
  
    typedef itk::VariableLengthVector< unsigned int > CountVectorType;
  
    typedef PixelType                                       MeasurementVectorType;
    typedef ObjectList<HistogramType>                       HistogramListType;
    typedef typename HistogramListType::Pointer             HistogramListPointerType;
    typedef typename std::vector<HistogramListPointerType>  ArrayHistogramListType;
  
  
    /** Set the no data value. These value are ignored in histogram
     *  computation if NoDataFlag is On
     */
    itkSetMacro(NoDataValue, InternalPixelType);
  
    /** Set the no data value. These value are ignored in histogram
     *  computation if NoDataFlag is On
     */
    itkGetConstReferenceMacro(NoDataValue, InternalPixelType);
  
    /** Set the NoDataFlag. If set to true, samples with values equal to
     *  m_NoDataValue are ignored.
     */
    itkSetMacro(NoDataFlag, bool);
  
    /** Get the NoDataFlag. If set to true, samples with values equal to
     *  m_NoDataValue are ignored.
     */
    itkGetMacro(NoDataFlag, bool);
  
    /** Toggle the NoDataFlag. If set to true, samples with values equal to
     *  m_NoDataValue are ignored.
     */
    itkBooleanMacro(NoDataFlag);
  
    inline void SetNumberOfBins( unsigned int i, CountVectorType::ValueType size )
    {
      m_Size[ i ] = size;
    }
  
    inline void SetNumberOfBins( const CountVectorType& size )
    {
      m_Size = size;
    }
  
    /** Return the computed histogram list */
    HistogramListType* GetHistogramListOutput();
    const HistogramListType* GetHistogramListOutput() const;
  
    /** Get the minimum values for histograms */
    itkGetConstReferenceMacro(HistogramMin,MeasurementVectorType);
  
    /** Set the minimum values for histograms */
    itkSetMacro(HistogramMin,MeasurementVectorType);
  
    /** Get the maximum values for histograms */
    itkGetConstReferenceMacro(HistogramMax,MeasurementVectorType);
  
    /** Set the maximum values for histograms */
    itkSetMacro(HistogramMax,MeasurementVectorType);
  
    /** Set the subsampling rate */
    itkSetMacro(SubSamplingRate, unsigned int);
  
    /** Get the subsampling rate */
    itkGetMacro(SubSamplingRate, unsigned int);
  
    /** Make a DataObject of the correct type to be used as the specified
     * output.
     */
    DataObjectPointer MakeOutput(DataObjectPointerArraySizeType idx) override;
    using Superclass::MakeOutput;
  
    /** Pass the input through unmodified. Do this by Grafting in the
     *  AllocateOutputs method.
     */
    void AllocateOutputs() override;
    void GenerateOutputInformation() override;
    void Synthetize(void) override;
    void Reset(void) override;
  
  protected:
    PersistentHistogramVectorImageFilter();
    ~PersistentHistogramVectorImageFilter() override {}
    void PrintSelf(std::ostream& os, itk::Indent indent) const override;
    /** Multi-thread version GenerateData. */
    void  ThreadedGenerateData(const RegionType& outputRegionForThread, itk::ThreadIdType threadId) override;
  
  private:
    PersistentHistogramVectorImageFilter(const Self &) = delete;
    void operator =(const Self&) = delete;
  
    ArrayHistogramListType   m_ThreadHistogramList;
    CountVectorType          m_Size;
    MeasurementVectorType    m_HistogramMin;
    MeasurementVectorType    m_HistogramMax;
    bool                     m_NoDataFlag;
    InternalPixelType        m_NoDataValue;
  
    /** Set the subsampling along each direction */
    unsigned int             m_SubSamplingRate;
  
  }; // end of class PersistentStatisticsVectorImageFilter
  
  /**===========================================================================*/
  
  /** \class StreamingHistogramVectorImageFilter
   * \brief This class streams the whole input image through the PersistentHistogramVectorImageFilter.
   *
   * This way, it allows computing the min/max of this image. It calls the
   * Reset() method of the PersistentHistogramVectorImageFilter before streaming the image and the
   * Synthetize() method of the PersistentHistogramVectorImageFilter after having streamed the image
   * to compute the statistics. The accessor on the results are wrapping the accessors of the
   * internal PersistentMinMaxImageFilter.
   *
   * \sa PersistentStatisticsVectorImageFilter
   * \sa PersistentImageFilter
   * \sa PersistentFilterStreamingDecorator
   * \sa StreamingImageVirtualWriter
   * \ingroup Streamed
   * \ingroup Multithreaded
   * \ingroup MathematicalStatisticsImageFilters
   *
   * \ingroup OTBStatistics
   */
  
  template<class TInputImage>
  class ITK_EXPORT StreamingHistogramVectorImageFilter :
    public PersistentFilterStreamingDecorator<PersistentHistogramVectorImageFilter<TInputImage> >
  {
  public:
    /** Standard Self typedef */
    typedef StreamingHistogramVectorImageFilter   Self;
    typedef PersistentFilterStreamingDecorator
    <PersistentHistogramVectorImageFilter<TInputImage> > Superclass;
    typedef itk::SmartPointer<Self>       Pointer;
    typedef itk::SmartPointer<const Self> ConstPointer;
  
    /** Type macro */
    itkNewMacro(Self);
  
    /** Creation through object factory macro */
    itkTypeMacro(StreamingHistogramVectorImageFilter, PersistentFilterStreamingDecorator);
  
    typedef TInputImage                                 InputImageType;
    typedef typename Superclass::FilterType             InternalFilterType;
  
    /** Types needed for histograms */
    typedef typename InternalFilterType::HistogramType      HistogramType;
    typedef typename InternalFilterType::HistogramListType  HistogramListType;
  
    using Superclass::SetInput;
    void SetInput(InputImageType * input)
    {
      this->GetFilter()->SetInput(input);
    }
    const InputImageType * GetInput()
    {
      return this->GetFilter()->GetInput();
    }
  
    /** Return the computed histogram */
    HistogramListType* GetHistogramList()
    {
      return this->GetFilter()->GetHistogramListOutput();
    }
  
  
  protected:
    /** Constructor */
    StreamingHistogramVectorImageFilter() {};
    /** Destructor */
    ~StreamingHistogramVectorImageFilter() override {}
  
  private:
    StreamingHistogramVectorImageFilter(const Self &) = delete;
    void operator =(const Self&) = delete;
  };
  
  } // end namespace otb
  
  #ifndef OTB_MANUAL_INSTANTIATION
  #include "otbStreamingHistogramVectorImageFilter.hxx"
  #endif
  
  #endif
  