text: /*=========================================================================
   *
   *  Copyright Insight Software Consortium
   *
   *  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.txt
   *
   *  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 itkStreamingImageFilter_h
  #define itkStreamingImageFilter_h
  
  #include "itkImageToImageFilter.h"
  #include "itkImageRegionSplitterBase.h"
  
  namespace itk
  {
  /** \class StreamingImageFilter
   * \brief Pipeline object to control data streaming for large data processing.
   *
   * StreamingImageFilter is a pipeline object that allows the user to control
   * how data is pulled through the pipeline.  To generate its
   * OutputRequestedRegion, this filter will divide the output into several
   * pieces (controlled by SetNumberOfStreamDivisions), and call the upstream
   * pipeline for each piece, tiling the individual outputs into one large
   * output. This reduces the memory footprint for the application since
   * each filter does not have to process the entire dataset at once.
   * This filter will produce the entire output as one image, but the upstream
   * filters will do their processing in pieces.
   *
   * \ingroup ITKSystemObjects
   * \ingroup DataProcessing
   * \ingroup ITKCommon
   */
  template< typename TInputImage, typename TOutputImage >
  class ITK_TEMPLATE_EXPORT StreamingImageFilter:public ImageToImageFilter< TInputImage, TOutputImage >
  {
  public:
    ITK_DISALLOW_COPY_AND_ASSIGN(StreamingImageFilter);
  
    /** Standard class type aliases. */
    using Self = StreamingImageFilter;
    using Superclass = ImageToImageFilter< TInputImage, TOutputImage >;
    using Pointer = SmartPointer< Self >;
    using ConstPointer = SmartPointer< const Self >;
  
    /** Method for creation through the object factory. */
    itkNewMacro(Self);
  
    /** Run-time type information (and related methods). */
    itkTypeMacro(StreamingImageFilter, ImageToImageFilter);
  
    /** Some type alias for the input and output. */
    using InputImageType = TInputImage;
    using InputImagePointer = typename InputImageType::Pointer;
    using InputImageRegionType = typename InputImageType::RegionType;
    using InputImagePixelType = typename InputImageType::PixelType;
  
    using OutputImageType = TOutputImage;
    using OutputImagePointer = typename OutputImageType::Pointer;
    using OutputImageRegionType = typename OutputImageType::RegionType;
    using OutputImagePixelType = typename OutputImageType::PixelType;
    using DataObjectPointer = typename Superclass::DataObjectPointer;
  
    /** Dimension of input image. */
    static constexpr unsigned int InputImageDimension = InputImageType::ImageDimension;
    static constexpr unsigned int OutputImageDimension = OutputImageType::ImageDimension;
  
    /** SmartPointer to a region splitting object */
    using SplitterType = ImageRegionSplitterBase;
    using RegionSplitterPointer = typename SplitterType::Pointer;
  
    /** Set the number of pieces to divide the input.  The upstream pipeline
     * will be executed this many times. */
    itkSetMacro(NumberOfStreamDivisions, unsigned int);
  
    /** Get the number of pieces to divide the input. The upstream pipeline
     * will be executed this many times. */
    itkGetConstReferenceMacro(NumberOfStreamDivisions, unsigned int);
  
    /** Get/Set the helper class for dividing the input into chunks. */
    itkSetObjectMacro(RegionSplitter, SplitterType);
    itkGetModifiableObjectMacro(RegionSplitter, SplitterType);
  
    /** Override UpdateOutputData() from ProcessObject to divide upstream
     * updates into pieces. This filter does not have a GenerateData()
     * or ThreadedGenerateData() method.  Instead, all the work is done
     * in UpdateOutputData() since it must update a little, execute a little,
     * update some more, execute some more, etc. */
    void UpdateOutputData(DataObject *output) override;
  
    /** Override PropagateRequestedRegion from ProcessObject
     *  Since inside UpdateOutputData we iterate over streaming pieces
     *  we don't need to proapage up the pipeline
     */
    void PropagateRequestedRegion(DataObject *output) override;
  
  #ifdef ITK_USE_CONCEPT_CHECKING
    // Begin concept checking
    itkConceptMacro( SameDimensionCheck,
                     ( Concept::SameDimension< InputImageDimension, OutputImageDimension > ) );
    itkConceptMacro( InputConvertibleToOutputCheck,
                     ( Concept::Convertible< InputImagePixelType, OutputImagePixelType > ) );
    // End concept checking
  #endif
  
  protected:
    StreamingImageFilter();
    ~StreamingImageFilter() override;
    void PrintSelf(std::ostream & os, Indent indent) const override;
  
  private:
    unsigned int          m_NumberOfStreamDivisions;
    RegionSplitterPointer m_RegionSplitter;
  };
  } // end namespace itk
  
  #ifndef ITK_MANUAL_INSTANTIATION
  #include "itkStreamingImageFilter.hxx"
  #endif
  
  #endif
  