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/*=========================================================================
Program: Insight Segmentation & Registration Toolkit
Module: $RCSfile: itkLevelSetFunctionWithRefitTerm.h,v $
Language: C++
Date: $Date: 2008-03-03 13:58:43 $
Version: $Revision: 1.7 $
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 __itkLevelSetFunctionWithRefitTerm_h_
#define __itkLevelSetFunctionWithRefitTerm_h_
#include "itkLevelSetFunction.h"
#include "itkSparseImage.h"
#include "itkNumericTraits.h"
namespace itk {
/**
* \class LevelSetFunctionWithRefitTerm
*
* \brief This class extends the LevelSetFunction class by adding a grow term
* based on a target curvature stored in a sparse image.
*
* \par
* We extend the LevelSetFunction class to add a refitting term. This refitting
* term forces the curvature of the level set interface to match a prescribed
* curvature. The prescribed curvature is provided in a sparse image
* format. The NodeType for the sparse image should contain the member
* variables m_Curvature and m_CurvatureFlag. The refitting term is defined as
* part of the propagation term of the original LevelSetFunction. To this
* purpose we defined the PropagationSpeed method which computes the refitting
* term and also adds to this term the value returned by the new virtual
* OtherPropagationSpeed. Therefore, classes derived from this class MUST NOT
* overwrite the PropagationSpeed method. Instead classes wishing to define a
* prapagtion term must define OtherPropagationSpeed.
*
* \par IMPORTANT
* Subclasses MUST NOT overwrite the PropagationSpeed method. Define
* OtherPropagationSpeed instead.
*/
template <class TImageType, class TSparseImageType>
class ITK_EXPORT LevelSetFunctionWithRefitTerm
: public LevelSetFunction<TImageType>
{
public:
/** Standard class typedefs. */
typedef LevelSetFunctionWithRefitTerm Self;
typedef LevelSetFunction<TImageType> Superclass;
typedef SmartPointer<Self> Pointer;
typedef SmartPointer<const Self> ConstPointer;
/** Run-time type information (and related methods) */
itkTypeMacro( LevelSetFunctionWithRefitTerm, LevelSetFunction );
/** Standard New macro. */
itkNewMacro (Self);
/** Extract some parameters from the superclass. */
typedef typename Superclass::ImageType ImageType;
typedef typename Superclass::FloatOffsetType FloatOffsetType;
typedef typename Superclass::ScalarValueType ScalarValueType;
typedef typename Superclass::GlobalDataStruct GlobalDataStruct;
typedef typename Superclass::NeighborhoodType NeighborhoodType;
typedef typename Superclass::NeighborhoodScalesType NeighborhoodScalesType;
typedef typename Superclass::TimeStepType TimeStepType;
/** Index type derived from the ImageType. */
typedef typename ImageType::IndexType IndexType;
/** The sparse image type used for the curvature target. */
typedef TSparseImageType SparseImageType;
/** The node type of the sparse image. */
typedef typename SparseImageType::NodeType NodeType;
/** The type for the normal vectors of the level set image. */
typedef typename NodeType::NodeDataType NormalVectorType;
/** Set the relative weight of the refitting term. */
void SetRefitWeight( const ScalarValueType w )
{
m_RefitWeight = w;
}
/** This is the weight for propagation terms (other than refitting)
* that can be defined by subclasses. */
void SetOtherPropagationWeight( const ScalarValueType w )
{
m_OtherPropagationWeight = w;
}
/** Sets the sparse image which has nodes containing the member variable
m_Curvature used in refitting. */
void SetSparseTargetImage( SparseImageType *im )
{ m_SparseTargetImage = im; }
/** Returns the sparse image. */
SparseImageType* GetSparseTargetImage() const
{ return m_SparseTargetImage; }
/** Computes the time step for an update given a global data structure.
* This calls the ComputeGlobalTimeStep method defined in LevelSetFunction
* and then imposes our own restrictions for the refitting term on the
* returned value. */
virtual TimeStepType ComputeGlobalTimeStep( void *GlobalData ) const;
protected:
/** The weight for the refitting term. */
ScalarValueType m_RefitWeight;
/** The weight for other scalar propagation terms that can be defined by
classes derived from this class. */
ScalarValueType m_OtherPropagationWeight;
LevelSetFunctionWithRefitTerm ();
void PrintSelf(std::ostream& os, Indent indent) const;
/** Computes the curvature of a level set neighbothood in a way that matches
the curvature computation from normal vectors. */
ScalarValueType ComputeCurvature( const NeighborhoodType & ) const;
/** Defines the virtual function in LevelSetFunction to add the refitting
* term. This function also calls OtherPropagationSpeed to provide a
* mechanism for subclasses to define other propagation terms. */
virtual ScalarValueType PropagationSpeed(const NeighborhoodType& ,
const FloatOffsetType &,
GlobalDataStruct * = 0 ) const;
/** Called by PropagationSpeed and added on to the refitting term. Function
* classes derived from this class should define this method for their
* propagation speed, NOT the actual PropagationSpeed method. */
virtual ScalarValueType OtherPropagationSpeed(const NeighborhoodType& ,
const FloatOffsetType &,
GlobalDataStruct * = 0) const
{
return NumericTraits<ScalarValueType>::Zero;
}
private:
LevelSetFunctionWithRefitTerm(const Self&); //purposely not implemented
void operator=(const Self&); //purposely not implemented
/** The sparse image that contains the target curvature information. */
typename SparseImageType::Pointer m_SparseTargetImage;
/** The minimum vector norm parameter. */
ScalarValueType m_MinVectorNorm;
/** Constants used in computations. */
static const unsigned long m_NumVertex;
static const ScalarValueType m_DimConst;
};
} // end namespace itk
#ifndef ITK_MANUAL_INSTANTIATION
#include "itkLevelSetFunctionWithRefitTerm.txx"
#endif
#endif
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