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 itkMeanImageFunction_hxx
  #define itkMeanImageFunction_hxx
  
  #include "itkMeanImageFunction.h"
  
  #include "itkImage.h"
  #include "itkShapedImageNeighborhoodRange.h"
  
  namespace itk
  {
  
  template <typename TInputImage, typename TCoordRep>
  MeanImageFunction<TInputImage, TCoordRep>::MeanImageFunction()
  
  {}
  
  template <typename TInputImage, typename TCoordRep>
  typename MeanImageFunction<TInputImage, TCoordRep>::RealType
  MeanImageFunction<TInputImage, TCoordRep>::EvaluateAtIndex(const IndexType & index) const
  {
    RealType sum;
  
    sum = NumericTraits<RealType>::ZeroValue();
  
    const InputImageType * const image = this->GetInputImage();
  
    if (image == nullptr)
    {
      return (NumericTraits<RealType>::max());
    }
  
    if (!this->IsInsideBuffer(index))
    {
      return (NumericTraits<RealType>::max());
    }
  
    const Experimental::ShapedImageNeighborhoodRange<const InputImageType> neighborhoodRange(
      *image, index, m_NeighborhoodOffsets);
  
    // Walk the neighborhood
    for (const InputPixelType pixelValue : neighborhoodRange)
    {
      sum += static_cast<RealType>(pixelValue);
    }
  
    return sum / static_cast<double>(neighborhoodRange.size());
  }
  
  
  template <typename TInputImage, typename TCoordRep>
  void
  MeanImageFunction<TInputImage, TCoordRep>::SetNeighborhoodRadius(const unsigned int radius)
  {
    if (m_NeighborhoodRadius != radius)
    {
      m_NeighborhoodOffsets = Experimental::GenerateRectangularImageNeighborhoodOffsets(ImageSizeType::Filled(radius));
      m_NeighborhoodRadius = radius;
      this->Modified();
    }
  }
  
  
  template <typename TInputImage, typename TCoordRep>
  void
  MeanImageFunction<TInputImage, TCoordRep>::PrintSelf(std::ostream & os, Indent indent) const
  {
    Superclass::PrintSelf(os, indent);
  
    os << indent << "NeighborhoodRadius: " << m_NeighborhoodRadius << std::endl;
  }
  } // end namespace itk
  
  #endif
  