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/*=========================================================================
Program: Insight Segmentation & Registration Toolkit
Module: $RCSfile: itkCurvesLevelSetFunction.txx,v $
Language: C++
Date: $Date: 2005-04-17 16:59:50 $
Version: $Revision: 1.3 $
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 __itkCurvesLevelSetFunction_txx_
#define __itkCurvesLevelSetFunction_txx_
#include "itkCurvesLevelSetFunction.h"
#include "itkImageRegionIterator.h"
#include "itkGradientRecursiveGaussianImageFilter.h"
#include "itkGradientImageFilter.h"
#include "itkVectorCastImageFilter.h"
namespace itk {
template< class TImageType, class TFeatureImageType>
void
CurvesLevelSetFunction< TImageType,TFeatureImageType>
::Initialize(const RadiusType &r)
{
Superclass::Initialize(r);
this->SetAdvectionWeight( NumericTraits<ScalarValueType>::One );
this->SetPropagationWeight( NumericTraits<ScalarValueType>::One );
this->SetCurvatureWeight( NumericTraits<ScalarValueType>::One );
}
template <class TImageType, class TFeatureImageType>
void CurvesLevelSetFunction<TImageType, TFeatureImageType>
::CalculateSpeedImage()
{
/* copy the feature image into the speed image */
ImageRegionConstIterator<FeatureImageType>
fit(this->GetFeatureImage(), this->GetFeatureImage()->GetRequestedRegion());
ImageRegionIterator<ImageType>
sit(this->GetSpeedImage(), this->GetFeatureImage()->GetRequestedRegion());
for ( fit.GoToBegin(), sit.GoToBegin(); ! fit.IsAtEnd(); ++sit, ++fit)
{
sit.Set( static_cast<ScalarValueType>( fit.Get() ) );
}
}
template <class TImageType, class TFeatureImageType>
void CurvesLevelSetFunction<TImageType, TFeatureImageType>
::CalculateAdvectionImage()
{
/* compute the gradient of the feature image. */
typename VectorImageType::Pointer gradientImage;
if (m_DerivativeSigma != NumericTraits<float>::Zero)
{
typedef GradientRecursiveGaussianImageFilter<FeatureImageType,VectorImageType>
DerivativeFilterType;
typename DerivativeFilterType::Pointer derivative = DerivativeFilterType::New();
derivative->SetInput( this->GetFeatureImage() );
derivative->SetSigma( m_DerivativeSigma );
derivative->Update();
gradientImage = derivative->GetOutput();
}
else
{
typedef GradientImageFilter<FeatureImageType> DerivativeFilterType;
typename DerivativeFilterType::Pointer derivative = DerivativeFilterType::New();
derivative->SetInput( this->GetFeatureImage() );
derivative->SetUseImageSpacingOn();
derivative->Update();
typedef typename DerivativeFilterType::OutputImageType DerivativeOutputImageType;
typedef VectorCastImageFilter<DerivativeOutputImageType,VectorImageType> GradientCasterType;
typename GradientCasterType::Pointer caster = GradientCasterType::New();
caster->SetInput(derivative->GetOutput());
caster->Update();
gradientImage = caster->GetOutput();
}
/* copy negative gradient into the advection image. */
ImageRegionIterator<VectorImageType>
dit( gradientImage, this->GetFeatureImage()->GetRequestedRegion() );
ImageRegionIterator<VectorImageType>
ait( this->GetAdvectionImage(), this->GetFeatureImage()->GetRequestedRegion() );
for( dit.GoToBegin(), ait.GoToBegin(); !dit.IsAtEnd(); ++dit, ++ait )
{
typename VectorImageType::PixelType v = dit.Get();
for ( unsigned int j = 0; j < ImageDimension; j++ )
{
v[j] *= -1.0L;
}
ait.Set( v);
}
}
} // end namespace itk
#endif
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