itkRescaleIntensityImageFilter.h

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/*=========================================================================
 *
 *  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 __itkRescaleIntensityImageFilter_h
#define __itkRescaleIntensityImageFilter_h

#include "itkUnaryFunctorImageFilter.h"

namespace itk
{
// This functor class applies a linear transformation A.x + B
// to input values.
namespace Functor
{
template< typename TInput, typename  TOutput >
class IntensityLinearTransform
{
public:
  typedef typename NumericTraits< TInput >::RealType RealType;
  IntensityLinearTransform()
  {
    m_Factor = 1.0;
    m_Offset = 0.0;
    m_Minimum = NumericTraits< TOutput >::NonpositiveMin();
    m_Maximum = NumericTraits< TOutput >::max();
  }

  ~IntensityLinearTransform() {}
  void SetFactor(RealType a) { m_Factor = a; }
  void SetOffset(RealType b) { m_Offset = b; }
  void SetMinimum(TOutput min) { m_Minimum = min; }
  void SetMaximum(TOutput max) { m_Maximum = max; }
  bool operator!=(const IntensityLinearTransform & other) const
  {
    if ( m_Factor != other.m_Factor
         || m_Offset != other.m_Offset
         || m_Maximum != other.m_Maximum
         || m_Minimum != other.m_Minimum )
      {
      return true;
      }
    return false;
  }

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

  inline TOutput operator()(const TInput & x) const
  {
    RealType value  = static_cast< RealType >( x ) * m_Factor + m_Offset;
    TOutput  result = static_cast< TOutput >( value );

    result = ( result > m_Maximum ) ? m_Maximum : result;
    result = ( result < m_Minimum ) ? m_Minimum : result;
    return result;
  }

private:
  RealType m_Factor;
  RealType m_Offset;
  TOutput  m_Maximum;
  TOutput  m_Minimum;
};
}  // end namespace functor

template< typename  TInputImage, typename  TOutputImage = TInputImage >
class ITK_EXPORT RescaleIntensityImageFilter:
  public
  UnaryFunctorImageFilter< TInputImage, TOutputImage,
                           Functor::IntensityLinearTransform<
                             typename TInputImage::PixelType,
                             typename TOutputImage::PixelType >   >
{
public:
  typedef RescaleIntensityImageFilter Self;
  typedef UnaryFunctorImageFilter<
    TInputImage, TOutputImage,
    Functor::IntensityLinearTransform<
      typename TInputImage::PixelType,
      typename TOutputImage::PixelType > >  Superclass;

  typedef SmartPointer< Self >       Pointer;
  typedef SmartPointer< const Self > ConstPointer;

  typedef typename TOutputImage::PixelType                   OutputPixelType;
  typedef typename TInputImage::PixelType                    InputPixelType;
  typedef typename NumericTraits< InputPixelType >::RealType RealType;

  itkNewMacro(Self);

  itkTypeMacro(RescaleIntensityImageFilter,
               UnaryFunctorImageFilter);

  itkSetMacro(OutputMinimum, OutputPixelType);
  itkSetMacro(OutputMaximum, OutputPixelType);
  itkGetConstReferenceMacro(OutputMinimum, OutputPixelType);
  itkGetConstReferenceMacro(OutputMaximum, OutputPixelType);

  itkGetConstReferenceMacro(Scale, RealType);
  itkGetConstReferenceMacro(Shift, RealType);

  itkGetConstReferenceMacro(InputMinimum, InputPixelType);
  itkGetConstReferenceMacro(InputMaximum, InputPixelType);

  void BeforeThreadedGenerateData(void);

  void PrintSelf(std::ostream & os, Indent indent) const;

#ifdef ITK_USE_CONCEPT_CHECKING

  itkConceptMacro( InputHasNumericTraitsCheck,
                   ( Concept::HasNumericTraits< InputPixelType > ) );
  itkConceptMacro( OutputHasNumericTraitsCheck,
                   ( Concept::HasNumericTraits< OutputPixelType > ) );
  itkConceptMacro( RealTypeMultiplyOperatorCheck,
                   ( Concept::MultiplyOperator< RealType > ) );
  itkConceptMacro( RealTypeAdditiveOperatorsCheck,
                   ( Concept::AdditiveOperators< RealType > ) );

#endif

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

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

  RealType m_Scale;
  RealType m_Shift;

  InputPixelType m_InputMinimum;
  InputPixelType m_InputMaximum;

  OutputPixelType m_OutputMinimum;
  OutputPixelType m_OutputMaximum;
};
} // end namespace itk

#ifndef ITK_MANUAL_INSTANTIATION
#include "itkRescaleIntensityImageFilter.hxx"
#endif

#endif