itkNearestNeighborExtrapolateImageFunction.h

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/*=========================================================================

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkNearestNeighborExtrapolateImageFunction.h,v $
  Language:  C++
  Date:      $Date: 2009-10-29 17:37:04 $
  Version:   $Revision: 1.12 $

  Copyright (c) Insight Software Consortium. All rights reserved.
  See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even 
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
     PURPOSE.  See the above copyright notices for more information.

=========================================================================*/
#ifndef __itkNearestNeighborExtrapolateImageFunction_h
#define __itkNearestNeighborExtrapolateImageFunction_h

#include "itkExtrapolateImageFunction.h"

namespace itk
{

template <class TInputImage, class TCoordRep = float>
class ITK_EXPORT NearestNeighborExtrapolateImageFunction : 
  public ExtrapolateImageFunction<TInputImage,TCoordRep> 
{
public:
  typedef NearestNeighborExtrapolateImageFunction         Self;
  typedef ExtrapolateImageFunction<TInputImage,TCoordRep> Superclass;
  typedef SmartPointer<Self>                              Pointer;
  typedef SmartPointer<const Self>                        ConstPointer;

  itkTypeMacro(NearestNeighborExtrapolateImageFunction, 
    InterpolateImageFunction);

  itkNewMacro(Self);  

  typedef typename Superclass::OutputType OutputType;

  typedef typename Superclass::InputImageType InputImageType;

  itkStaticConstMacro(ImageDimension, unsigned int,Superclass::ImageDimension);

  typedef typename Superclass::IndexType      IndexType;
  typedef typename Superclass::IndexValueType IndexValueType;

  typedef typename Superclass::ContinuousIndexType ContinuousIndexType;

  virtual OutputType EvaluateAtContinuousIndex( 
    const ContinuousIndexType & index ) const
    {
    IndexType nindex;
    for ( unsigned int j = 0; j < ImageDimension; j++ )
      {
      nindex[j] = Math::RoundHalfIntegerUp<IndexValueType>( index[j] );
      if ( nindex[j] < this->GetStartIndex()[j] ) 
        { 
        nindex[j] = this->GetStartIndex()[j]; 
        }
      else if ( nindex[j] > this->GetEndIndex()[j] ) 
        { 
        nindex[j] = this->GetEndIndex()[j];
        }
      }
    return static_cast<OutputType>( this->GetInputImage()->GetPixel( nindex ) );
    }


  virtual OutputType EvaluateAtIndex( 
    const IndexType & index ) const
    {
    IndexType nindex;
    for ( unsigned int j = 0; j < ImageDimension; j++ )
      {
      if ( index[j] < this->GetStartIndex()[j] ) 
        { 
        nindex[j] = this->GetStartIndex()[j]; 
        }
      else if ( index[j] > this->GetEndIndex()[j] ) 
        { 
        nindex[j] = this->GetEndIndex()[j];
        }
      else
        {
        nindex[j] = index[j];
        }
      }
    return static_cast<OutputType>( this->GetInputImage()->GetPixel( nindex ) );
    }


protected:
  NearestNeighborExtrapolateImageFunction(){};
  ~NearestNeighborExtrapolateImageFunction(){};
  void PrintSelf(std::ostream& os, Indent indent) const
   { Superclass::PrintSelf( os, indent ); }

private:
  NearestNeighborExtrapolateImageFunction(const Self&); //purposely not implemented
  void operator=(const Self&); //purposely not implemented

};

} // end namespace itk

#endif