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/*=========================================================================
Program: Insight Segmentation & Registration Toolkit
Module: $RCSfile: itkShapePriorSegmentationLevelSetFunction.txx,v $
Language: C++
Date: $Date: 2008-03-03 13:58:42 $
Version: $Revision: 1.8 $
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 __itkShapePriorSegmentationLevelSetFunction_txx_
#define __itkShapePriorSegmentationLevelSetFunction_txx_
#include "itkShapePriorSegmentationLevelSetFunction.h"
namespace itk {
/**
* Constructor
*/
template <class TImageType, class TFeatureImageType>
ShapePriorSegmentationLevelSetFunction<TImageType, TFeatureImageType>
::ShapePriorSegmentationLevelSetFunction()
{
m_ShapeFunction = NULL;
m_ShapePriorWeight = NumericTraits<ScalarValueType>::Zero;
}
/**
* PrintSelf
*/
template <class TImageType, class TFeatureImageType>
void
ShapePriorSegmentationLevelSetFunction<TImageType, TFeatureImageType>
::PrintSelf( std::ostream& os, Indent indent) const
{
Superclass::PrintSelf( os, indent );
os << indent << "ShapeFunction: " << m_ShapeFunction.GetPointer() << std::endl;
os << indent << "ShapePriorWeight: " << m_ShapePriorWeight << std::endl;
}
/**
* Compute the equation value.
*/
template <class TImageType, class TFeatureImageType>
typename ShapePriorSegmentationLevelSetFunction<TImageType, TFeatureImageType>
::PixelType
ShapePriorSegmentationLevelSetFunction<TImageType, TFeatureImageType>
::ComputeUpdate(
const NeighborhoodType &neighborhood,
void *gd,
const FloatOffsetType& offset )
{
// Compute the generic level set update using superclass
PixelType value = this->Superclass::ComputeUpdate( neighborhood, gd, offset );
// Add the shape prior term
if ( m_ShapeFunction && m_ShapePriorWeight != NumericTraits<ScalarValueType>::Zero )
{
IndexType idx = neighborhood.GetIndex();
ContinuousIndex<double,ImageDimension> cdx;
for( unsigned int i = 0; i < ImageDimension; ++i )
{
cdx[i] = static_cast<double>( idx[i] ) - offset[i];
}
typename ShapeFunctionType::PointType point;
this->GetFeatureImage()->TransformContinuousIndexToPhysicalPoint( cdx, point );
ScalarValueType shape_term = m_ShapePriorWeight *
( m_ShapeFunction->Evaluate( point ) - neighborhood.GetCenterPixel() );
value += shape_term;
// collect max change to be used for calculating the time step
ShapePriorGlobalDataStruct *globalData = (ShapePriorGlobalDataStruct *)gd;
globalData->m_MaxShapePriorChange
= vnl_math_max( globalData->m_MaxShapePriorChange, vnl_math_abs( shape_term ) );
}
return value;
};
/**
* Compute the global time step.
*/
template <class TImageType, class TFeatureImageType>
typename ShapePriorSegmentationLevelSetFunction<TImageType, TFeatureImageType>
::TimeStepType
ShapePriorSegmentationLevelSetFunction<TImageType, TFeatureImageType>
::ComputeGlobalTimeStep( void * gd ) const
{
TimeStepType dt;
ShapePriorGlobalDataStruct *d = (ShapePriorGlobalDataStruct *) gd;
d->m_MaxAdvectionChange += d->m_MaxPropagationChange + d->m_MaxShapePriorChange;
if (vnl_math_abs(d->m_MaxCurvatureChange) > 0.0)
{
if (d->m_MaxAdvectionChange > 0.0)
{
dt = vnl_math_min((this->m_WaveDT / d->m_MaxAdvectionChange),
( this->m_DT / d->m_MaxCurvatureChange ));
}
else
{
dt = this->m_DT / d->m_MaxCurvatureChange;
}
}
else
{
if (d->m_MaxAdvectionChange > 0.0)
{
dt = this->m_WaveDT / d->m_MaxAdvectionChange;
}
else
{
dt = 0.0;
}
}
double maxScaleCoefficient = 0.0;
for (unsigned int i=0; i<ImageDimension; i++)
{
maxScaleCoefficient = vnl_math_max(this->m_ScaleCoefficients[i],maxScaleCoefficient);
}
dt /= maxScaleCoefficient;
// reset the values
d->m_MaxAdvectionChange = 0;
d->m_MaxPropagationChange= 0;
d->m_MaxCurvatureChange = 0;
d->m_MaxShapePriorChange = 0;
return dt;
}
} // end namespace itk
#endif
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