text: /*=========================================================================
   *
   *  Copyright NumFOCUS
   *
   *  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 itkNormalizeToConstantImageFilter_h
  #define itkNormalizeToConstantImageFilter_h
  
  #include "itkImageToImageFilter.h"
  #include "itkConceptChecking.h"
  
  namespace itk
  {
  
  /** \class NormalizeToConstantImageFilter
   *
   * \brief Scales image pixel intensities to make the sum of all pixels
   * equal a user-defined constant.
   *
   * The default value of the constant is 1. It can be changed with
   * SetConstant().
   *
   * This transform is especially useful for normalizing a convolution
   * kernel.
   *
   * This code was contributed in the Insight Journal paper: "FFT based
   * convolution" by Lehmann G.
   * https://hdl.handle.net/10380/3154
   *
   * \author Gaetan Lehmann. Biologie du Developpement et de la Reproduction, INRA de Jouy-en-Josas, France.
   *
   * \sa NormalizeImageFilter
   * \sa StatisticsImageFilter
   * \sa DivideImageFilter
   *
   * \ingroup MathematicalImageFilters
   * \ingroup ITKImageIntensity
   *
   * \sphinx
   * \sphinxexample{Filtering/ImageIntensity/ScalePixelSumToConstant,Scale All Pixel's Sum To Constant}
   * \endsphinx
   */
  template <typename TInputImage, typename TOutputImage>
  class ITK_TEMPLATE_EXPORT NormalizeToConstantImageFilter : public ImageToImageFilter<TInputImage, TOutputImage>
  {
  public:
    ITK_DISALLOW_COPY_AND_ASSIGN(NormalizeToConstantImageFilter);
  
    /** Standard class type aliases. */
    using Self = NormalizeToConstantImageFilter;
  
    using Superclass = ImageToImageFilter<TInputImage, TOutputImage>;
  
    using Pointer = SmartPointer<Self>;
    using ConstPointer = SmartPointer<const Self>;
  
    /** Some convenient type alias. */
    using InputImageType = TInputImage;
    using OutputImageType = TOutputImage;
    using InputImagePointer = typename InputImageType::Pointer;
    using InputImageConstPointer = typename InputImageType::ConstPointer;
    using InputImagePixelType = typename InputImageType::PixelType;
    using OutputImagePointer = typename OutputImageType::Pointer;
    using OutputImageConstPointer = typename OutputImageType::ConstPointer;
    using OutputImagePixelType = typename OutputImageType::PixelType;
    using RegionType = typename InputImageType::RegionType;
    using IndexType = typename InputImageType::IndexType;
    using SizeType = typename InputImageType::SizeType;
  
    using RealType = typename NumericTraits<InputImagePixelType>::RealType;
  
    /** ImageDimension constants */
    static constexpr unsigned int InputImageDimension = TInputImage::ImageDimension;
    static constexpr unsigned int OutputImageDimension = TOutputImage::ImageDimension;
    static constexpr unsigned int ImageDimension = TOutputImage::ImageDimension;
  
    /** Standard New method. */
    itkNewMacro(Self);
  
    /** Runtime information support. */
    itkTypeMacro(NormalizeToConstantImageFilter, ImageToImageFilter);
  
    /** Set/get the normalization constant. */
    itkSetMacro(Constant, RealType);
    itkGetConstMacro(Constant, RealType);
  
  #ifdef ITK_USE_CONCEPT_CHECKING
    // Begin concept checking
    itkConceptMacro(InputHasPixelTraitsCheck, (Concept::HasPixelTraits<InputImagePixelType>));
    itkConceptMacro(InputHasNumericTraitsCheck, (Concept::HasNumericTraits<InputImagePixelType>));
    // End concept checking
  #endif
  
  protected:
    NormalizeToConstantImageFilter();
    ~NormalizeToConstantImageFilter() override = default;
    void
    PrintSelf(std::ostream & os, Indent indent) const override;
  
    void
    GenerateInputRequestedRegion() override;
  
    void
    GenerateData() override;
  
  private:
    RealType m_Constant;
  
  }; // end of class
  } // end namespace itk
  
  #ifndef ITK_MANUAL_INSTANTIATION
  #  include "itkNormalizeToConstantImageFilter.hxx"
  #endif
  
  #endif
  