itkSquaredFunctionImageToImageMetric.h

Go to the documentation of this file.

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

  NifTK: A software platform for medical image computing.

  Copyright (c) University College London (UCL). All rights reserved.

  This software is distributed WITHOUT ANY WARRANTY; without even
  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  PURPOSE.

  See LICENSE.txt in the top level directory for details.

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

#ifndef itkSquaredFunctionImageToImageMetric_h
#define itkSquaredFunctionImageToImageMetric_h

#include <itkImageToImageMetric.h>
#include <itkCovariantVector.h>
#include <itkPoint.h>

namespace itk
{
template < typename TFixedImage, typename TMovingImage > 
class ITK_EXPORT SquaredFunctionImageToImageMetric : 
    public ImageToImageMetric< TFixedImage, TMovingImage>
{
public:

  typedef SquaredFunctionImageToImageMetric               Self;
  typedef ImageToImageMetric<TFixedImage, TMovingImage >  Superclass;
  typedef SmartPointer<Self>                              Pointer;
  typedef SmartPointer<const Self>                        ConstPointer;

  itkNewMacro(Self);
 
  itkTypeMacro(SquaredFunctionImageToImageMetric, ImageToImageMetric);

  typedef typename Superclass::TransformType              TransformType;
  typedef typename Superclass::TransformParametersType    TransformParametersType;
  typedef typename Superclass::DerivativeType             DerivativeType;
  typedef typename Superclass::MeasureType                MeasureType;

  void Initialize() throw (ExceptionObject) {};

  MeasureType GetValue( const TransformParametersType & parameters ) const
    {
      MeasureType result = 0;
      for (unsigned int i = 0; i < parameters.GetSize(); i++)
        {
          result += (parameters.GetElement(i) * parameters.GetElement(i));
        }
      return result;
    }

  void GetDerivative( const TransformParametersType & parameters,
                      DerivativeType  & derivative ) const
    {
      const unsigned int numberOfParameters = parameters.GetSize();
        derivative = DerivativeType( numberOfParameters );
  
      for (unsigned int i = 0; i < parameters.GetSize(); i++)
        {
          derivative[i] = 2.0 * parameters.GetElement(i);
        }
    }

  void GetValueAndDerivative( const TransformParametersType & parameters,
                              MeasureType& value, DerivativeType& derivative ) const
    {
      value = this->GetValue(parameters);
      this->GetDerivative(parameters, derivative);
    }
  
protected:
  
  SquaredFunctionImageToImageMetric() {};
  virtual ~SquaredFunctionImageToImageMetric() {};

private:
  
  SquaredFunctionImageToImageMetric(const Self&); // purposefully not implemented
  void operator=(const Self&);    // purposefully not implemented
  
};

} // end namespace itk

#endif