itkVectorIndexSelectionCastImageFilter.h

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

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkVectorIndexSelectionCastImageFilter.h,v $
  Language:  C++
  Date:      $Date: 2009-04-01 14:42:12 $
  Version:   $Revision: 1.17 $

  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 __itkVectorIndexSelectionCastImageFilter_h
#define __itkVectorIndexSelectionCastImageFilter_h

#include "itkUnaryFunctorImageFilter.h"

namespace itk
{
  
namespace Functor {  
  
template< class TInput, class TOutput>
class VectorIndexSelectionCast
{
public:
  VectorIndexSelectionCast() {m_Index = 0;}
  ~VectorIndexSelectionCast() {}

  unsigned int GetIndex() const { return m_Index; }
  void SetIndex(unsigned int i) { m_Index = i; }

  bool operator!=( const VectorIndexSelectionCast & other ) const
    {
    if( m_Index != other.m_Index )
      {
      return true;
      }
    return false;
    }
  bool operator==( const VectorIndexSelectionCast & other ) const
    {
    return !(*this != other);
    }
  inline TOutput operator()( const TInput & A ) const
    {
    return static_cast<TOutput>( A[m_Index] );
    }
      
private:
  unsigned int m_Index;   
}; 
}

template <class TInputImage, class TOutputImage>
class ITK_EXPORT VectorIndexSelectionCastImageFilter :
    public
UnaryFunctorImageFilter<TInputImage,TOutputImage, 
                        Functor::VectorIndexSelectionCast< typename TInputImage::PixelType, 
                                                           typename TOutputImage::PixelType>   >
{
public:
  typedef VectorIndexSelectionCastImageFilter Self;
  typedef UnaryFunctorImageFilter<
    TInputImage,TOutputImage, 
    Functor::VectorIndexSelectionCast< typename TInputImage::PixelType, 
                                       typename TOutputImage::PixelType> >
                                              Superclass;
  typedef SmartPointer<Self>                  Pointer;
  typedef SmartPointer<const Self>            ConstPointer;

  itkNewMacro(Self);

  itkTypeMacro(VectorIndexSelectionCastImageFilter, 
               UnaryFunctorImageFilter);

  void SetIndex(unsigned int i)
    {
    if (i != this->GetFunctor().GetIndex())
      {
      this->GetFunctor().SetIndex(i);
      this->Modified();
      }
    }
  unsigned int GetIndex(void) const 
    { 
    return this->GetFunctor().GetIndex(); 
    }

#ifdef ITK_USE_CONCEPT_CHECKING

  itkConceptMacro(InputHasNumericTraitsCheck,
    (Concept::HasNumericTraits<typename TInputImage::PixelType::ValueType>));

#endif

protected:
  VectorIndexSelectionCastImageFilter() {}
  virtual ~VectorIndexSelectionCastImageFilter() {}
    
  virtual void BeforeThreadedGenerateData()
    {
    const unsigned int index = this->GetIndex();
    const TInputImage * image = this->GetInput();

    const unsigned int numberOfRunTimeComponents = 
               image->GetNumberOfComponentsPerPixel();
    
    typedef typename TInputImage::PixelType    PixelType;

    typedef typename itk::NumericTraits< PixelType >::RealType 
                                                         PixelRealType;

    typedef typename itk::NumericTraits< PixelType >::ScalarRealType 
                                                         PixelScalarRealType;

    const unsigned int numberOfCompileTimeComponents =
             sizeof( PixelRealType ) / sizeof( PixelScalarRealType );

    unsigned int numberOfComponents = numberOfRunTimeComponents;

    if( numberOfCompileTimeComponents > numberOfRunTimeComponents )
      {
      numberOfComponents = numberOfCompileTimeComponents;
      }
      
    if( index >= numberOfComponents )
      {
        itkExceptionMacro(
            << "Selected index = " << index 
            << " is greater than the number of components = "
            << numberOfComponents );
      }
    }
    

private:
  VectorIndexSelectionCastImageFilter(const Self&); //purposely not implemented
  void operator=(const Self&); //purposely not implemented
};
 
} // end namespace itk

#endif