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/*=========================================================================
Program: Insight Segmentation & Registration Toolkit
Module: $RCSfile: itkMeanSquareRegistrationFunction.txx,v $
Language: C++
Date: $Date: 2008-02-03 04:05:28 $
Version: $Revision: 1.13 $
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 _itkMeanSquareRegistrationFunction_txx_
#define _itkMeanSquareRegistrationFunction_txx_
#include "itkMeanSquareRegistrationFunction.h"
#include "itkExceptionObject.h"
#include "vnl/vnl_math.h"
namespace itk {
/*
* Default constructor
*/
template <class TFixedImage, class TMovingImage, class TDeformationField>
MeanSquareRegistrationFunction<TFixedImage,TMovingImage,TDeformationField>
::MeanSquareRegistrationFunction()
{
RadiusType r;
unsigned int j;
for( j = 0; j < ImageDimension; j++ )
{
r[j] = 0;
}
this->SetRadius(r);
this->SetEnergy(0.0);
m_TimeStep = 1.0;
m_DenominatorThreshold = 1e-9;
m_IntensityDifferenceThreshold = 0.001;
this->SetMovingImage(NULL);
this->SetFixedImage(NULL);
m_FixedImageSpacing.Fill( 1.0 );
m_FixedImageOrigin.Fill( 0.0 );
m_FixedImageGradientCalculator = GradientCalculatorType::New();
typename DefaultInterpolatorType::Pointer interp =
DefaultInterpolatorType::New();
m_MovingImageInterpolator = static_cast<InterpolatorType*>(
interp.GetPointer() );
}
/*
* Standard "PrintSelf" method.
*/
template <class TFixedImage, class TMovingImage, class TDeformationField>
void
MeanSquareRegistrationFunction<TFixedImage,TMovingImage,TDeformationField>
::PrintSelf(std::ostream& os, Indent indent) const
{
Superclass::PrintSelf(os, indent);
/*
os << indent << "MovingImageIterpolator: ";
os << m_MovingImageInterpolator.GetPointer() << std::endl;
os << indent << "FixedImageGradientCalculator: ";
os << m_FixedImageGradientCalculator.GetPointer() << std::endl;
os << indent << "DenominatorThreshold: ";
os << m_DenominatorThreshold << std::endl;
os << indent << "IntensityDifferenceThreshold: ";
os << m_IntensityDifferenceThreshold << std::endl;
*/
}
/*
* Set the function state values before each iteration
*/
template <class TFixedImage, class TMovingImage, class TDeformationField>
void
MeanSquareRegistrationFunction<TFixedImage,TMovingImage,TDeformationField>
::InitializeIteration()
{
if( !this->GetMovingImage() || !this->GetFixedImage() || !m_MovingImageInterpolator )
{
itkExceptionMacro( << "MovingImage, FixedImage and/or Interpolator not set" );
}
// cache fixed image information
m_FixedImageSpacing = this->GetFixedImage()->GetSpacing();
m_FixedImageOrigin = this->GetFixedImage()->GetOrigin();
// setup gradient calculator
m_FixedImageGradientCalculator->SetInputImage( this->GetFixedImage() );
// setup moving image interpolator
m_MovingImageInterpolator->SetInputImage( this->GetMovingImage() );
this->SetEnergy(0.0);
}
/*
* Compute update at a non boundary neighbourhood
*/
template <class TFixedImage, class TMovingImage, class TDeformationField>
typename MeanSquareRegistrationFunction<TFixedImage,TMovingImage,TDeformationField>
::PixelType
MeanSquareRegistrationFunction<TFixedImage,TMovingImage,TDeformationField>
::ComputeUpdate(const NeighborhoodType &it, void * itkNotUsed(globalData),
const FloatOffsetType& itkNotUsed(offset))
{
//std::cout << " Update " << std::endl;
PixelType update;
unsigned int j;
IndexType index = it.GetIndex();
// Get fixed image related information
double fixedValue;
CovariantVectorType fixedGradient;
double fixedGradientSquaredMagnitude = 0;
// Note: no need to check the index is within
// fixed image buffer. This is done by the external filter.
fixedValue = (double) this->GetFixedImage()->GetPixel( index );
fixedGradient = m_FixedImageGradientCalculator->EvaluateAtIndex( index );
for( j = 0; j < ImageDimension; j++ )
{
fixedGradientSquaredMagnitude += vnl_math_sqr( fixedGradient[j] ) * m_FixedImageSpacing[j];
}
// Get moving image related information
double movingValue;
PointType mappedPoint;
DeformationFieldPixelType itvec=this->GetDeformationField()->GetPixel(index);
for( j = 0; j < ImageDimension; j++ )
{
mappedPoint[j] = double( index[j] ) * m_FixedImageSpacing[j] +
m_FixedImageOrigin[j];
// mappedPoint[j] += it.GetCenterPixel()[j];
mappedPoint[j] += itvec[j];
}
if( m_MovingImageInterpolator->IsInsideBuffer( mappedPoint ) )
{
movingValue = m_MovingImageInterpolator->Evaluate( mappedPoint );
}
else
{
movingValue = 0.0;
}
// Compute update
double speedValue = fixedValue - movingValue;
this->m_Energy+=speedValue*speedValue;
bool normalizemetric=this->GetNormalizeGradient();
double denominator = 1.0;
if (normalizemetric)
{
denominator = speedValue*speedValue *fixedGradientSquaredMagnitude;
denominator = vcl_sqrt(denominator);
}
if (denominator == 0) denominator=1.0;
if ( vnl_math_abs(speedValue) < m_IntensityDifferenceThreshold ||
denominator < m_DenominatorThreshold )
{
for( j = 0; j < ImageDimension; j++ )
{
update[j] = 0.0;
}
return update;
}
for( j = 0; j < ImageDimension; j++ )
{
update[j] = speedValue * fixedGradient[j] * vnl_math_sqr(m_FixedImageSpacing[j]) /
denominator*this->m_GradientStep;
}
return update;
}
} // end namespace itk
#endif
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