itkScalarConnectedComponentImageFilter.h

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

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkScalarConnectedComponentImageFilter.h,v $
  Language:  C++
  Date:      $Date: 2009-07-05 17:36:22 $
  Version:   $Revision: 1.9 $

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

  Portions of this code are covered under the VTK copyright.
  See VTKCopyright.txt or http://www.kitware.com/VTKCopyright.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 __itkScalarConnectedComponentImageFilter_h
#define __itkScalarConnectedComponentImageFilter_h

#include "vnl/vnl_math.h"
#include "itkNumericTraits.h"
#include "itkConnectedComponentFunctorImageFilter.h"

namespace itk
{

namespace Functor {  
  
template<class TInput>
class SimilarPixelsFunctor
{
public:
  SimilarPixelsFunctor()
    {
    m_Threshold = NumericTraits<TInput>::Zero;
    }

  ~SimilarPixelsFunctor() 
    {
    }

  bool operator!=( const SimilarPixelsFunctor & other ) const
    {
    if( m_Threshold != other.m_Threshold )
      {
      return true;
      }
    return false;
    }

  bool operator==( const SimilarPixelsFunctor & other ) const
    {
    return !(*this != other);
    }

  void SetDistanceThreshold(const TInput &thresh) 
    {
    m_Threshold = thresh;
    }

  TInput GetDistanceThreshold() 
    {
    return (m_Threshold);
    }
  
  bool operator()(const TInput &a, const TInput &b) const
    {
    typedef typename NumericTraits<TInput>::RealType InputRealType;
    TInput absDifference = static_cast<TInput>( vnl_math_abs( 
                           static_cast<InputRealType>(a)
                           - static_cast<InputRealType>(b) ) );
    if( absDifference <= m_Threshold )
      {
      return true;
      }
    else
      {
      return false;
      }
    }

protected:
  TInput m_Threshold;
                            
};

} // end namespace Functor 

template <class TInputImage, class TOutputImage, class TMaskImage=TInputImage>
class ITK_EXPORT ScalarConnectedComponentImageFilter :
    public ConnectedComponentFunctorImageFilter<TInputImage,TOutputImage,
             Functor::SimilarPixelsFunctor<typename TInputImage::ValueType>,
                                           TMaskImage> 
{
public:
  typedef ScalarConnectedComponentImageFilter Self;
  typedef ConnectedComponentFunctorImageFilter<
    TInputImage,TOutputImage, 
    Functor::SimilarPixelsFunctor<typename TInputImage::ValueType>,
    TMaskImage>                               Superclass;
  typedef SmartPointer<Self>                  Pointer;
  typedef SmartPointer<const Self>            ConstPointer;

  itkNewMacro(Self);

  itkTypeMacro(ScalarConnectedComponentImageFilter,ConnectedComponentFunctorImageFilter);

  typedef typename TInputImage::PixelType  InputPixelType;
  
  virtual void SetDistanceThreshold(const InputPixelType& thresh)
    {this->GetFunctor().SetDistanceThreshold(thresh);}

  virtual InputPixelType GetDistanceThreshold()
    {return (this->GetFunctor().GetDistanceThreshold());}

#ifdef ITK_USE_CONCEPT_CHECKING

  itkConceptMacro(InputEqualityComparableCheck,
    (Concept::EqualityComparable<InputPixelType>));
  itkConceptMacro(OutputEqualityComparableCheck,
    (Concept::EqualityComparable<typename TOutputImage::PixelType>));
  itkConceptMacro(MaskEqualityComparableCheck,
    (Concept::EqualityComparable<typename TMaskImage::PixelType>));
  itkConceptMacro(OutputIncrementDecrementOperatorsCheck,
    (Concept::IncrementDecrementOperators<typename TOutputImage::PixelType>));

#endif

protected:
  ScalarConnectedComponentImageFilter() {};
  virtual ~ScalarConnectedComponentImageFilter() {};

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

};

} // end namespace itk

#endif