freMeanVectorFieldGenerator.txx

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

  Program:   F.R.E.E. - flexible registration evaluation engine
  Version:   v.1.0.0
  Date:      $Date: 2006/09/01 12:00:00 $
  Module:    $RCSfile: freMeanVectorFieldGenerator.txx,v $
  Language:  C++



  Copyright (c) 2007 Ralf o Floca (Department of Medical Informatics,
  Institute for Medical Biometry and Informatics, University of Heidelberg,
  Germany). All rights reserved.
  See FREECopyright.txt or http://www.mi.med.uni-hd.de/free/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 __freMeanVectorFieldGenerator_txx
#define __freMeanVectorFieldGenerator_txx

#include "freMeanVectorFieldGenerator.h"
#include "itkCastImageFilter.h"

namespace FREE
{

template <class TInputVectorField,class TOutputVectorField>
void
MeanVectorFieldGenerator<TInputVectorField, TOutputVectorField>::
ResizeSumField(OutputImageType* elementField)
{
        if (!m_iFieldCount)
        {
                if (!m_bUserRegion)
                {
                        m_OutputRegion = elementField->GetLargestPossibleRegion();
                        m_OutputOrigin = elementField->GetOrigin();
                }

                m_SumVectorField = OutputImageType::New();
                m_SumVectorField->SetOrigin(m_OutputOrigin);
                m_SumVectorField->SetSpacing(elementField->GetSpacing());
                m_SumVectorField->SetRegions(m_OutputRegion);
                m_SumVectorField->Allocate();

                //Reset the transformation field to no transformation (all vectors components are 0)
                OutputVectorType pixel;
    for (int iIndex=0; iIndex < OutputVectorType::GetVectorDimension(); iIndex++) pixel[iIndex]=0;      
                m_SumVectorField->FillBuffer(pixel);
        }
};

template <class TInputVectorField,class TOutputVectorField>
void
MeanVectorFieldGenerator<TInputVectorField, TOutputVectorField>::
AddField(const InputImageType* vectorField)
{
        typedef itk::CastImageFilter<InputImageType,OutputImageType> CasterType;

        typename CasterType::Pointer caster = CasterType::New();
        caster->SetInput(vectorField);

        typename OutputImageType::Pointer smpCastedInput = caster->GetOutput();
        caster->Update();

        ResizeSumField(smpCastedInput);

        OutputRegionType newRegion = vectorField->GetLargestPossibleRegion();

        if (newRegion.Crop(m_OutputRegion))
        { //new field is inside the output region, so add values to the sum, otherwise safe time
                // and skip;
                typedef itk::ImageRegionIterator<OutputImageType> OutputIteratorType;
                typedef itk::ImageRegionConstIterator<OutputImageType> OutputConstIteratorType;

    OutputIteratorType sumIterator(m_SumVectorField,newRegion);
    OutputConstIteratorType iterator(smpCastedInput,newRegion);

    for (sumIterator.GoToBegin(), iterator.GoToBegin(); !(sumIterator.IsAtEnd()); ++sumIterator, ++iterator)
    {
      OutputVectorType result = sumIterator.Get();
      result = result+iterator.Get();
      sumIterator.Set(result);  
                }
        }

        m_iFieldCount++;
};
  
template <class TInputVectorField,class TOutputVectorField>
typename MeanVectorFieldGenerator<TInputVectorField, TOutputVectorField>::OutputImagePointer
MeanVectorFieldGenerator<TInputVectorField, TOutputVectorField>::
GetOutput (void) const
{
        OutputImagePointer outputField = OutputImageType::New();
        outputField->SetOrigin(m_SumVectorField->GetOrigin());
        outputField->SetSpacing(m_SumVectorField->GetSpacing());
        outputField->SetRegions(m_SumVectorField->GetLargestPossibleRegion());
        outputField->Allocate();

        typedef itk::ImageRegionIterator<OutputImageType> OutputIteratorType;
        typedef itk::ImageRegionConstIterator<OutputImageType> OutputConstIteratorType;

  OutputConstIteratorType sumIterator(m_SumVectorField,m_OutputRegion);
  OutputIteratorType outIterator(outputField,m_OutputRegion);

        typedef typename OutputVectorType::ValueType OutputVectorValueType;
  OutputVectorValueType factor = 0;

        if (m_iFieldCount) factor = 1.0/(OutputVectorValueType)m_iFieldCount;

        for (sumIterator.GoToBegin(),outIterator.GoToBegin(); !(sumIterator.IsAtEnd()); ++sumIterator, ++outIterator)
        {
    OutputVectorType result = sumIterator.Get();
    result = result*factor;
                outIterator.Set(result);
        }

        return outputField;
};

template <class TInputVectorField,class TOutputVectorField>
void
MeanVectorFieldGenerator<TInputVectorField, TOutputVectorField>::
Reset()
{
        m_iFieldCount = 0;
        m_bUserRegion = false;
};

template <class TInputVectorField,class TOutputVectorField>
MeanVectorFieldGenerator<TInputVectorField, TOutputVectorField>::
MeanVectorFieldGenerator()
{
        Reset();
};

template <class TInputVectorField,class TOutputVectorField>
MeanVectorFieldGenerator<TInputVectorField, TOutputVectorField>::
~MeanVectorFieldGenerator()
{
};

template <class TInputVectorField,class TOutputVectorField>
typename MeanVectorFieldGenerator<TInputVectorField, TOutputVectorField>::OutputRegionType
MeanVectorFieldGenerator<TInputVectorField, TOutputVectorField>::
GetOutputRegion() const
{
        return m_OutputRegion;
};

template <class TInputVectorField,class TOutputVectorField>
void
MeanVectorFieldGenerator<TInputVectorField, TOutputVectorField>::
SetOutputGeometry(const OutputRegionType& outputRegion, const OutputPointType& origin)
{
        m_OutputRegion = outputRegion;
        m_OutputOrigin = origin;
        m_bUserRegion = true;
};

}//End of Namespace free

#endif

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