// gets integrated into the main directories.
#include "itkConfigure.h"
-#ifdef ITK_USE_OPTIMIZED_REGISTRATION_METHODS
#include "itkOptMattesMutualInformationImageToImageMetricFor3DBLUTFFD.txx"
-#else
-
-
-#include "itkMattesMutualInformationImageToImageMetricFor3DBLUTFFD.h"
-#include "itkBSplineInterpolateImageFunction.h"
-#include "itkCovariantVector.h"
-#include "itkImageRandomConstIteratorWithIndex.h"
-#include "itkImageRegionConstIterator.h"
-#include "itkImageRegionIterator.h"
-#include "itkImageIterator.h"
-#include "vnl/vnl_math.h"
-#include "itkBSplineDeformableTransform.h"
-
-namespace itk
-{
-
-
-/**
- * Constructor
- */
-template < class TFixedImage, class TMovingImage >
-MattesMutualInformationImageToImageMetricFor3DBLUTFFD<TFixedImage,TMovingImage>
-::MattesMutualInformationImageToImageMetricFor3DBLUTFFD()
-{
-
- m_NumberOfSpatialSamples = 500;
- m_NumberOfHistogramBins = 50;
-
- this->SetComputeGradient(false); // don't use the default gradient for now
-
- m_InterpolatorIsBSpline = false;
- m_TransformIsBSpline = false;
-
- // Initialize PDFs to NULL
- m_JointPDF = NULL;
- m_JointPDFDerivatives = NULL;
-
- m_UseExplicitPDFDerivatives = true;
-
- typename BSplineTransformType::Pointer transformer =
- BSplineTransformType::New();
- this->SetTransform (transformer);
-
- typename BSplineInterpolatorType::Pointer interpolator =
- BSplineInterpolatorType::New();
- this->SetInterpolator (interpolator);
-
- // Initialize memory
- m_MovingImageNormalizedMin = 0.0;
- m_FixedImageNormalizedMin = 0.0;
- m_MovingImageTrueMin = 0.0;
- m_MovingImageTrueMax = 0.0;
- m_FixedImageBinSize = 0.0;
- m_MovingImageBinSize = 0.0;
- m_CubicBSplineDerivativeKernel = NULL;
- m_BSplineInterpolator = NULL;
- m_DerivativeCalculator = NULL;
- m_NumParametersPerDim = 0;
- m_NumBSplineWeights = 0;
- m_BSplineTransform = NULL;
- m_NumberOfParameters = 0;
- m_UseAllPixels = false;
- m_ReseedIterator = false;
- m_RandomSeed = -1;
- m_UseCachingOfBSplineWeights = true;
-}
-
-
-/**
- * Print out internal information about this class
- */
-template < class TFixedImage, class TMovingImage >
-void
-MattesMutualInformationImageToImageMetricFor3DBLUTFFD<TFixedImage,TMovingImage>
-::PrintSelf(std::ostream& os, Indent indent) const
-{
-
- Superclass::PrintSelf(os, indent);
-
- os << indent << "NumberOfSpatialSamples: ";
- os << m_NumberOfSpatialSamples << std::endl;
- os << indent << "NumberOfHistogramBins: ";
- os << m_NumberOfHistogramBins << std::endl;
- os << indent << "UseAllPixels: ";
- os << m_UseAllPixels << std::endl;
-
- // Debugging information
- os << indent << "NumberOfParameters: ";
- os << m_NumberOfParameters << std::endl;
- os << indent << "FixedImageNormalizedMin: ";
- os << m_FixedImageNormalizedMin << std::endl;
- os << indent << "MovingImageNormalizedMin: ";
- os << m_MovingImageNormalizedMin << std::endl;
- os << indent << "MovingImageTrueMin: ";
- os << m_MovingImageTrueMin << std::endl;
- os << indent << "MovingImageTrueMax: ";
- os << m_MovingImageTrueMax << std::endl;
- os << indent << "FixedImageBinSize: ";
- os << m_FixedImageBinSize << std::endl;
- os << indent << "MovingImageBinSize: ";
- os << m_MovingImageBinSize << std::endl;
- os << indent << "InterpolatorIsBSpline: ";
- os << m_InterpolatorIsBSpline << std::endl;
- os << indent << "TransformIsBSpline: ";
- os << m_TransformIsBSpline << std::endl;
- os << indent << "UseCachingOfBSplineWeights: ";
- os << m_UseCachingOfBSplineWeights << std::endl;
- os << indent << "UseExplicitPDFDerivatives: ";
- os << m_UseExplicitPDFDerivatives << std::endl;
-
-}
-
-
-/**
- * Initialize
- */
-template <class TFixedImage, class TMovingImage>
-void
-MattesMutualInformationImageToImageMetricFor3DBLUTFFD<TFixedImage,TMovingImage>
-::Initialize(void) throw ( ExceptionObject )
-{
- this->Superclass::Initialize();
-
- // Cache the number of transformation parameters
- m_NumberOfParameters = this->m_Transform->GetNumberOfParameters();
-
- /**
- * Compute the minimum and maximum for the FixedImage over
- * the FixedImageRegion.
- *
- * NB: We can't use StatisticsImageFilter to do this because
- * the filter computes the min/max for the largest possible region
- */
- double fixedImageMin = NumericTraits<double>::max();
- double fixedImageMax = NumericTraits<double>::NonpositiveMin();
-
- typedef ImageRegionConstIterator<FixedImageType> FixedIteratorType;
- FixedIteratorType fixedImageIterator(
- this->m_FixedImage, this->GetFixedImageRegion() );
-
- for ( fixedImageIterator.GoToBegin();
- !fixedImageIterator.IsAtEnd(); ++fixedImageIterator ) {
-
- double sample = static_cast<double>( fixedImageIterator.Get() );
-
- if ( sample < fixedImageMin ) {
- fixedImageMin = sample;
- }
-
- if ( sample > fixedImageMax ) {
- fixedImageMax = sample;
- }
- }
-
-
- /**
- * Compute the minimum and maximum for the entire moving image
- * in the buffer.
- */
- double movingImageMin = NumericTraits<double>::max();
- double movingImageMax = NumericTraits<double>::NonpositiveMin();
-
- typedef ImageRegionConstIterator<MovingImageType> MovingIteratorType;
- MovingIteratorType movingImageIterator(
- this->m_MovingImage, this->m_MovingImage->GetBufferedRegion() );
-
- for ( movingImageIterator.GoToBegin();
- !movingImageIterator.IsAtEnd(); ++movingImageIterator) {
- double sample = static_cast<double>( movingImageIterator.Get() );
-
- if ( sample < movingImageMin ) {
- movingImageMin = sample;
- }
-
- if ( sample > movingImageMax ) {
- movingImageMax = sample;
- }
- }
-
- m_MovingImageTrueMin = movingImageMin;
- m_MovingImageTrueMax = movingImageMax;
-
- itkDebugMacro( " FixedImageMin: " << fixedImageMin <<
- " FixedImageMax: " << fixedImageMax << std::endl );
- itkDebugMacro( " MovingImageMin: " << movingImageMin <<
- " MovingImageMax: " << movingImageMax << std::endl );
-
-
- /**
- * Compute binsize for the histograms.
- *
- * The binsize for the image intensities needs to be adjusted so that
- * we can avoid dealing with boundary conditions using the cubic
- * spline as the Parzen window. We do this by increasing the size
- * of the bins so that the joint histogram becomes "padded" at the
- * borders. Because we are changing the binsize,
- * we also need to shift the minimum by the padded amount in order to
- * avoid minimum values filling in our padded region.
- *
- * Note that there can still be non-zero bin values in the padded region,
- * it's just that these bins will never be a central bin for the Parzen
- * window.
- *
- */
- const int padding = 2; // this will pad by 2 bins
-
- m_FixedImageBinSize = ( fixedImageMax - fixedImageMin ) /
- static_cast<double>( m_NumberOfHistogramBins - 2 * padding );
- m_FixedImageNormalizedMin = fixedImageMin / m_FixedImageBinSize -
- static_cast<double>( padding );
-
- m_MovingImageBinSize = ( movingImageMax - movingImageMin ) /
- static_cast<double>( m_NumberOfHistogramBins - 2 * padding );
- m_MovingImageNormalizedMin = movingImageMin / m_MovingImageBinSize -
- static_cast<double>( padding );
-
-
- itkDebugMacro( "FixedImageNormalizedMin: " << m_FixedImageNormalizedMin );
- itkDebugMacro( "MovingImageNormalizedMin: " << m_MovingImageNormalizedMin );
- itkDebugMacro( "FixedImageBinSize: " << m_FixedImageBinSize );
- itkDebugMacro( "MovingImageBinSize; " << m_MovingImageBinSize );
-
- if( m_UseAllPixels ) {
- m_NumberOfSpatialSamples =
- this->GetFixedImageRegion().GetNumberOfPixels();
- }
-
- /**
- * Allocate memory for the fixed image sample container.
- */
- m_FixedImageSamples.resize( m_NumberOfSpatialSamples );
-
-
- /**
- * Allocate memory for the marginal PDF and initialize values
- * to zero. The marginal PDFs are stored as std::vector.
- */
- m_FixedImageMarginalPDF.resize( m_NumberOfHistogramBins, 0.0 );
- m_MovingImageMarginalPDF.resize( m_NumberOfHistogramBins, 0.0 );
-
- /**
- * Allocate memory for the joint PDF and joint PDF derivatives.
- * The joint PDF and joint PDF derivatives are store as itk::Image.
- */
- m_JointPDF = JointPDFType::New();
-
- // Instantiate a region, index, size
- JointPDFRegionType jointPDFRegion;
- JointPDFIndexType jointPDFIndex;
- JointPDFSizeType jointPDFSize;
-
- // Deallocate the memory that may have been allocated for
- // previous runs of the metric.
- this->m_JointPDFDerivatives = NULL; // by destroying the dynamic array
- this->m_PRatioArray.SetSize( 1, 1 ); // and by allocating very small the static ones
- this->m_MetricDerivative = DerivativeType( 1 );
-
- //
- // Now allocate memory according to the user-selected method.
- //
- if( this->m_UseExplicitPDFDerivatives ) {
- this->m_JointPDFDerivatives = JointPDFDerivativesType::New();
- JointPDFDerivativesRegionType jointPDFDerivativesRegion;
- JointPDFDerivativesIndexType jointPDFDerivativesIndex;
- JointPDFDerivativesSizeType jointPDFDerivativesSize;
-
- // For the derivatives of the joint PDF define a region starting from {0,0,0}
- // with size {m_NumberOfParameters,m_NumberOfHistogramBins,
- // m_NumberOfHistogramBins}. The dimension represents transform parameters,
- // fixed image parzen window index and moving image parzen window index,
- // respectively.
- jointPDFDerivativesIndex.Fill( 0 );
- jointPDFDerivativesSize[0] = m_NumberOfParameters;
- jointPDFDerivativesSize[1] = m_NumberOfHistogramBins;
- jointPDFDerivativesSize[2] = m_NumberOfHistogramBins;
-
- jointPDFDerivativesRegion.SetIndex( jointPDFDerivativesIndex );
- jointPDFDerivativesRegion.SetSize( jointPDFDerivativesSize );
-
- // Set the regions and allocate
- m_JointPDFDerivatives->SetRegions( jointPDFDerivativesRegion );
- m_JointPDFDerivatives->Allocate();
- } else {
- /** Allocate memory for helper array that will contain the pRatios
- * for each bin of the joint histogram. This is part of the effort
- * for flattening the computation of the PDF Jacobians.
- */
- this->m_PRatioArray.SetSize( this->m_NumberOfHistogramBins, this->m_NumberOfHistogramBins );
- this->m_MetricDerivative = DerivativeType( this->GetNumberOfParameters() );
- }
-
- // For the joint PDF define a region starting from {0,0}
- // with size {m_NumberOfHistogramBins, m_NumberOfHistogramBins}.
- // The dimension represents fixed image parzen window index
- // and moving image parzen window index, respectively.
- jointPDFIndex.Fill( 0 );
- jointPDFSize.Fill( m_NumberOfHistogramBins );
-
- jointPDFRegion.SetIndex( jointPDFIndex );
- jointPDFRegion.SetSize( jointPDFSize );
-
- // Set the regions and allocate
- m_JointPDF->SetRegions( jointPDFRegion );
- m_JointPDF->Allocate();
-
-
- /**
- * Setup the kernels used for the Parzen windows.
- */
- m_CubicBSplineKernel = CubicBSplineFunctionType::New();
- m_CubicBSplineDerivativeKernel = CubicBSplineDerivativeFunctionType::New();
-
-
- if( m_UseAllPixels ) {
- /**
- * Take all the pixels within the fixed image region)
- * to create the sample points list.
- */
- this->SampleFullFixedImageDomain( m_FixedImageSamples );
- } else {
- /**
- * Uniformly sample the fixed image (within the fixed image region)
- * to create the sample points list.
- */
- this->SampleFixedImageDomain( m_FixedImageSamples );
- }
-
- /**
- * Pre-compute the fixed image parzen window index for
- * each point of the fixed image sample points list.
- */
- this->ComputeFixedImageParzenWindowIndices( m_FixedImageSamples );
-
- /**
- * Check if the interpolator is of type BSplineInterpolateImageFunction.
- * If so, we can make use of its EvaluateDerivatives method.
- * Otherwise, we instantiate an external central difference
- * derivative calculator.
- *
- * TODO: Also add it the possibility of using the default gradient
- * provided by the superclass.
- *
- */
- m_InterpolatorIsBSpline = true;
-
- BSplineInterpolatorType * testPtr = dynamic_cast<BSplineInterpolatorType *>(
- this->m_Interpolator.GetPointer() );
- if ( !testPtr ) {
- m_InterpolatorIsBSpline = false;
-
- m_DerivativeCalculator = DerivativeFunctionType::New();
-
-#ifdef ITK_USE_ORIENTED_IMAGE_DIRECTION
- m_DerivativeCalculator->UseImageDirectionOn();
-#endif
-
- m_DerivativeCalculator->SetInputImage( this->m_MovingImage );
-
- m_BSplineInterpolator = NULL;
- itkDebugMacro( "Interpolator is not BSpline" );
- } else {
- m_BSplineInterpolator = testPtr;
-
-#ifdef ITK_USE_ORIENTED_IMAGE_DIRECTION
- m_BSplineInterpolator->UseImageDirectionOn();
-#endif
-
- m_DerivativeCalculator = NULL;
- itkDebugMacro( "Interpolator is BSpline" );
- }
-
- /**
- * Check if the transform is of type BSplineDeformableTransform.
- *
- * If so, several speed up features are implemented.
- * [1] Precomputing the results of bulk transform for each sample point.
- * [2] Precomputing the BSpline weights for each sample point,
- * to be used later to directly compute the deformation vector
- * [3] Precomputing the indices of the parameters within the
- * the support region of each sample point.
- */
- m_TransformIsBSpline = true;
-
- BSplineTransformType * testPtr2 = dynamic_cast<BSplineTransformType *>(
- this->m_Transform.GetPointer() );
- if( !testPtr2 ) {
- m_TransformIsBSpline = false;
- m_BSplineTransform = NULL;
- itkDebugMacro( "Transform is not BSplineDeformable" );
- } else {
- m_BSplineTransform = testPtr2;
- m_NumParametersPerDim =
- m_BSplineTransform->GetNumberOfParametersPerDimension();
- m_NumBSplineWeights = m_BSplineTransform->GetNumberOfWeights();
- itkDebugMacro( "Transform is BSplineDeformable" );
- }
-
- if( this->m_TransformIsBSpline ) {
- // First, deallocate memory that may have been used from previous run of the Metric
- this->m_BSplineTransformWeightsArray.SetSize( 1, 1 );
- this->m_BSplineTransformIndicesArray.SetSize( 1, 1 );
- this->m_PreTransformPointsArray.resize( 1 );
- this->m_WithinSupportRegionArray.resize( 1 );
- this->m_Weights.SetSize( 1 );
- this->m_Indices.SetSize( 1 );
-
-
- if( this->m_UseCachingOfBSplineWeights ) {
- m_BSplineTransformWeightsArray.SetSize(
- m_NumberOfSpatialSamples, m_NumBSplineWeights );
- m_BSplineTransformIndicesArray.SetSize(
- m_NumberOfSpatialSamples, m_NumBSplineWeights );
- m_PreTransformPointsArray.resize( m_NumberOfSpatialSamples );
- m_WithinSupportRegionArray.resize( m_NumberOfSpatialSamples );
-
- this->PreComputeTransformValues();
- } else {
- this->m_Weights.SetSize( this->m_NumBSplineWeights );
- this->m_Indices.SetSize( this->m_NumBSplineWeights );
- }
-
- for ( unsigned int j = 0; j < FixedImageDimension; j++ ) {
- m_ParametersOffset[j] = j *
- m_BSplineTransform->GetNumberOfParametersPerDimension();
- }
- }
-
-}
-
-
-/**
- * Uniformly sample the fixed image domain using a random walk
- */
-template < class TFixedImage, class TMovingImage >
-void
-MattesMutualInformationImageToImageMetricFor3DBLUTFFD<TFixedImage,TMovingImage>
-::SampleFixedImageDomain( FixedImageSpatialSampleContainer& samples )
-{
-
- // Set up a random interator within the user specified fixed image region.
- typedef ImageRandomConstIteratorWithIndex<FixedImageType> RandomIterator;
- RandomIterator randIter( this->m_FixedImage, this->GetFixedImageRegion() );
-
- randIter.SetNumberOfSamples( m_NumberOfSpatialSamples );
- randIter.GoToBegin();
-
- typename FixedImageSpatialSampleContainer::iterator iter;
- typename FixedImageSpatialSampleContainer::const_iterator end=samples.end();
-
- if( this->m_FixedImageMask ) {
-
- InputPointType inputPoint;
-
- iter=samples.begin();
- int count = 0;
- int samples_found = 0;
- int maxcount = m_NumberOfSpatialSamples * 10;
- while( iter != end ) {
-
- if ( count > maxcount ) {
-#if 0
- itkExceptionMacro(
- "Drew too many samples from the mask (is it too small?): "
- << maxcount << std::endl );
-#else
-samples.resize(samples_found);
-// this->SetNumberOfSpatialSamples(sample_found);
-break;
-#endif
- }
- count++;
-
- // Get sampled index
- FixedImageIndexType index = randIter.GetIndex();
- // Check if the Index is inside the mask, translate index to point
- this->m_FixedImage->TransformIndexToPhysicalPoint( index, inputPoint );
-
- // If not inside the mask, ignore the point
- if( !this->m_FixedImageMask->IsInside( inputPoint ) ) {
- ++randIter; // jump to another random position
- continue;
- }
-
- // Get sampled fixed image value
- (*iter).FixedImageValue = randIter.Get();
- // Translate index to point
- (*iter).FixedImagePointValue = inputPoint;
- samples_found++;
- // Jump to random position
- ++randIter;
- ++iter;
- }
- } else {
- for( iter=samples.begin(); iter != end; ++iter ) {
- // Get sampled index
- FixedImageIndexType index = randIter.GetIndex();
- // Get sampled fixed image value
- (*iter).FixedImageValue = randIter.Get();
- // Translate index to point
- this->m_FixedImage->TransformIndexToPhysicalPoint( index,
- (*iter).FixedImagePointValue );
- // Jump to random position
- ++randIter;
-
- }
- }
-}
-
-/**
- * Sample the fixed image domain using all pixels in the Fixed image region
- */
-template < class TFixedImage, class TMovingImage >
-void
-MattesMutualInformationImageToImageMetricFor3DBLUTFFD<TFixedImage,TMovingImage>
-::SampleFullFixedImageDomain( FixedImageSpatialSampleContainer& samples )
-{
-
- // Set up a region interator within the user specified fixed image region.
- typedef ImageRegionConstIteratorWithIndex<FixedImageType> RegionIterator;
- RegionIterator regionIter( this->m_FixedImage, this->GetFixedImageRegion() );
-
- regionIter.GoToBegin();
-
- typename FixedImageSpatialSampleContainer::iterator iter;
- typename FixedImageSpatialSampleContainer::const_iterator end=samples.end();
-
- if( this->m_FixedImageMask ) {
- InputPointType inputPoint;
-
- iter=samples.begin();
- unsigned long nSamplesPicked = 0;
-
- while( iter != end && !regionIter.IsAtEnd() ) {
- // Get sampled index
- FixedImageIndexType index = regionIter.GetIndex();
- // Check if the Index is inside the mask, translate index to point
- this->m_FixedImage->TransformIndexToPhysicalPoint( index, inputPoint );
-
- // If not inside the mask, ignore the point
- if( !this->m_FixedImageMask->IsInside( inputPoint ) ) {
- ++regionIter; // jump to next pixel
- continue;
- }
-
- // Get sampled fixed image value
- (*iter).FixedImageValue = regionIter.Get();
- // Translate index to point
- (*iter).FixedImagePointValue = inputPoint;
-
- ++regionIter;
- ++iter;
- ++nSamplesPicked;
- }
-
- // If we picked fewer samples than the desired number,
- // resize the container
- if (nSamplesPicked != this->m_NumberOfSpatialSamples) {
- this->m_NumberOfSpatialSamples = nSamplesPicked;
- samples.resize(this->m_NumberOfSpatialSamples);
- }
- } else { // not restricting sample throwing to a mask
-
- // cannot sample more than the number of pixels in the image region
- if ( this->m_NumberOfSpatialSamples
- > this->GetFixedImageRegion().GetNumberOfPixels()) {
- this->m_NumberOfSpatialSamples
- = this->GetFixedImageRegion().GetNumberOfPixels();
- samples.resize(this->m_NumberOfSpatialSamples);
- }
-
- for( iter=samples.begin(); iter != end; ++iter ) {
- // Get sampled index
- FixedImageIndexType index = regionIter.GetIndex();
- // Get sampled fixed image value
- (*iter).FixedImageValue = regionIter.Get();
- // Translate index to point
- this->m_FixedImage->TransformIndexToPhysicalPoint( index,
- (*iter).FixedImagePointValue );
- ++regionIter;
- }
- }
-}
-
-/**
- * Uniformly sample the fixed image domain using a random walk
- */
-template < class TFixedImage, class TMovingImage >
-void
-MattesMutualInformationImageToImageMetricFor3DBLUTFFD<TFixedImage,TMovingImage>
-::ComputeFixedImageParzenWindowIndices(
- FixedImageSpatialSampleContainer& samples )
-{
-
- typename FixedImageSpatialSampleContainer::iterator iter;
- typename FixedImageSpatialSampleContainer::const_iterator end=samples.end();
-
- for( iter=samples.begin(); iter != end; ++iter ) {
-
- // Determine parzen window arguments (see eqn 6 of Mattes paper [2]).
- double windowTerm =
- static_cast<double>( (*iter).FixedImageValue ) / m_FixedImageBinSize -
- m_FixedImageNormalizedMin;
- unsigned int pindex = static_cast<unsigned int>( vcl_floor(windowTerm ) );
-
- // Make sure the extreme values are in valid bins
- if ( pindex < 2 ) {
- pindex = 2;
- } else if ( pindex > (m_NumberOfHistogramBins - 3) ) {
- pindex = m_NumberOfHistogramBins - 3;
- }
-
- (*iter).FixedImageParzenWindowIndex = pindex;
-
- }
-
-}
-
-/**
- * Get the match Measure
- */
-template < class TFixedImage, class TMovingImage >
-typename MattesMutualInformationImageToImageMetricFor3DBLUTFFD<TFixedImage,TMovingImage>
-::MeasureType
-MattesMutualInformationImageToImageMetricFor3DBLUTFFD<TFixedImage,TMovingImage>
-::GetValue( const ParametersType& parameters ) const
-{
-
- // Reset marginal pdf to all zeros.
- // Assumed the size has already been set to NumberOfHistogramBins
- // in Initialize().
- for ( unsigned int j = 0; j < m_NumberOfHistogramBins; j++ ) {
- m_FixedImageMarginalPDF[j] = 0.0;
- m_MovingImageMarginalPDF[j] = 0.0;
- }
-
- // Reset the joint pdfs to zero
- m_JointPDF->FillBuffer( 0.0 );
-
- // Set up the parameters in the transform
- this->m_Transform->SetParameters( parameters );
-
-
- // Declare iterators for iteration over the sample container
- typename FixedImageSpatialSampleContainer::const_iterator fiter;
- typename FixedImageSpatialSampleContainer::const_iterator fend =
- m_FixedImageSamples.end();
-
- unsigned long nSamples=0;
- unsigned long nFixedImageSamples=0;
-
-
- for ( fiter = m_FixedImageSamples.begin(); fiter != fend; ++fiter ) {
-
- // Get moving image value
- MovingImagePointType mappedPoint;
- bool sampleOk;
- double movingImageValue;
-
- this->TransformPoint( nFixedImageSamples, parameters, mappedPoint,
- sampleOk, movingImageValue );
-
- ++nFixedImageSamples;
-
- if( sampleOk ) {
-
- ++nSamples;
-
- /**
- * Compute this sample's contribution to the marginal and
- * joint distributions.
- *
- */
-
- // Determine parzen window arguments (see eqn 6 of Mattes paper [2])
- double movingImageParzenWindowTerm =
- movingImageValue / m_MovingImageBinSize - m_MovingImageNormalizedMin;
- unsigned int movingImageParzenWindowIndex =
- static_cast<unsigned int>( vcl_floor(movingImageParzenWindowTerm ) );
-
- // Make sure the extreme values are in valid bins
- if ( movingImageParzenWindowIndex < 2 ) {
- movingImageParzenWindowIndex = 2;
- } else if ( movingImageParzenWindowIndex > (m_NumberOfHistogramBins - 3) ) {
- movingImageParzenWindowIndex = m_NumberOfHistogramBins - 3;
- }
-
-
- // Since a zero-order BSpline (box car) kernel is used for
- // the fixed image marginal pdf, we need only increment the
- // fixedImageParzenWindowIndex by value of 1.0.
- m_FixedImageMarginalPDF[(*fiter).FixedImageParzenWindowIndex] +=
- static_cast<PDFValueType>( 1 );
-
- /**
- * The region of support of the parzen window determines which bins
- * of the joint PDF are effected by the pair of image values.
- * Since we are using a cubic spline for the moving image parzen
- * window, four bins are affected. The fixed image parzen window is
- * a zero-order spline (box car) and thus effects only one bin.
- *
- * The PDF is arranged so that moving image bins corresponds to the
- * zero-th (column) dimension and the fixed image bins corresponds
- * to the first (row) dimension.
- *
- */
-
- // Pointer to affected bin to be updated
- JointPDFValueType *pdfPtr = m_JointPDF->GetBufferPointer() +
- ( (*fiter).FixedImageParzenWindowIndex
- * m_JointPDF->GetOffsetTable()[1] );
-
- // Move the pointer to the first affected bin
- int pdfMovingIndex = static_cast<int>( movingImageParzenWindowIndex ) - 1;
- pdfPtr += pdfMovingIndex;
-
- for (; pdfMovingIndex <= static_cast<int>( movingImageParzenWindowIndex )
- + 2;
- pdfMovingIndex++, pdfPtr++ ) {
-
- // Update PDF for the current intensity pair
- double movingImageParzenWindowArg =
- static_cast<double>( pdfMovingIndex ) -
- static_cast<double>( movingImageParzenWindowTerm );
-
- *(pdfPtr) += static_cast<PDFValueType>(
- m_CubicBSplineKernel->Evaluate( movingImageParzenWindowArg ) );
-
- } //end parzen windowing for loop
-
- } //end if-block check sampleOk
- } // end iterating over fixed image spatial sample container for loop
-
- itkDebugMacro( "Ratio of voxels mapping into moving image buffer: "
- << nSamples << " / " << m_NumberOfSpatialSamples
- << std::endl );
-
- if( nSamples < m_NumberOfSpatialSamples / 16 ) {
- itkExceptionMacro( "Too many samples map outside moving image buffer: "
- << nSamples << " / " << m_NumberOfSpatialSamples
- << std::endl );
- }
-
- this->m_NumberOfPixelsCounted = nSamples;
-
-
- /**
- * Normalize the PDFs, compute moving image marginal PDF
- *
- */
- typedef ImageRegionIterator<JointPDFType> JointPDFIteratorType;
- JointPDFIteratorType jointPDFIterator ( m_JointPDF,
- m_JointPDF->GetBufferedRegion() );
-
- jointPDFIterator.GoToBegin();
-
- // Compute joint PDF normalization factor
- // (to ensure joint PDF sum adds to 1.0)
- double jointPDFSum = 0.0;
-
- while( !jointPDFIterator.IsAtEnd() ) {
- jointPDFSum += jointPDFIterator.Get();
- ++jointPDFIterator;
- }
-
- if ( jointPDFSum == 0.0 ) {
- itkExceptionMacro( "Joint PDF summed to zero" );
- }
-
-
- // Normalize the PDF bins
- jointPDFIterator.GoToEnd();
- while( !jointPDFIterator.IsAtBegin() ) {
- --jointPDFIterator;
- jointPDFIterator.Value() /= static_cast<PDFValueType>( jointPDFSum );
- }
-
-
- // Normalize the fixed image marginal PDF
- double fixedPDFSum = 0.0;
- for( unsigned int bin = 0; bin < m_NumberOfHistogramBins; bin++ ) {
- fixedPDFSum += m_FixedImageMarginalPDF[bin];
- }
-
- if ( fixedPDFSum == 0.0 ) {
- itkExceptionMacro( "Fixed image marginal PDF summed to zero" );
- }
-
- for( unsigned int bin=0; bin < m_NumberOfHistogramBins; bin++ ) {
- m_FixedImageMarginalPDF[bin] /= static_cast<PDFValueType>( fixedPDFSum );
- }
-
-
- // Compute moving image marginal PDF by summing over fixed image bins.
- typedef ImageLinearIteratorWithIndex<JointPDFType> JointPDFLinearIterator;
- JointPDFLinearIterator linearIter( m_JointPDF,
- m_JointPDF->GetBufferedRegion() );
-
- linearIter.SetDirection( 1 );
- linearIter.GoToBegin();
- unsigned int movingIndex1 = 0;
-
- while( !linearIter.IsAtEnd() ) {
-
- double sum = 0.0;
-
- while( !linearIter.IsAtEndOfLine() ) {
- sum += linearIter.Get();
- ++linearIter;
- }
-
- m_MovingImageMarginalPDF[movingIndex1] = static_cast<PDFValueType>(sum);
-
- linearIter.NextLine();
- ++movingIndex1;
-
- }
-
- /**
- * Compute the metric by double summation over histogram.
- */
-
- // Setup pointer to point to the first bin
- JointPDFValueType * jointPDFPtr = m_JointPDF->GetBufferPointer();
-
- // Initialze sum to zero
- double sum = 0.0;
-
- for( unsigned int fixedIndex = 0;
- fixedIndex < m_NumberOfHistogramBins;
- ++fixedIndex ) {
-
- double fixedImagePDFValue = m_FixedImageMarginalPDF[fixedIndex];
-
- for( unsigned int movingIndex = 0;
- movingIndex < m_NumberOfHistogramBins;
- ++movingIndex, jointPDFPtr++ ) {
-
- double movingImagePDFValue = m_MovingImageMarginalPDF[movingIndex];
- double jointPDFValue = *(jointPDFPtr);
-
- // check for non-zero bin contribution
- if( jointPDFValue > 1e-16 && movingImagePDFValue > 1e-16 ) {
-
- double pRatio = vcl_log(jointPDFValue / movingImagePDFValue );
- if( fixedImagePDFValue > 1e-16) {
- sum += jointPDFValue * ( pRatio - vcl_log(fixedImagePDFValue ) );
- }
-
- } // end if-block to check non-zero bin contribution
- } // end for-loop over moving index
- } // end for-loop over fixed index
-
- return static_cast<MeasureType>( -1.0 * sum );
-
-}
-
-
-/**
- * Get the both Value and Derivative Measure
- */
-template < class TFixedImage, class TMovingImage >
-void
-MattesMutualInformationImageToImageMetricFor3DBLUTFFD<TFixedImage,TMovingImage>
-::GetValueAndDerivative(
- const ParametersType& parameters,
- MeasureType& value,
- DerivativeType& derivative) const
-{
-
- // Set output values to zero
- value = NumericTraits< MeasureType >::Zero;
-
- if( this->m_UseExplicitPDFDerivatives ) {
- m_JointPDFDerivatives->FillBuffer( 0.0 );
- derivative = DerivativeType( this->GetNumberOfParameters() );
- derivative.Fill( NumericTraits< MeasureType >::Zero );
- } else {
- this->m_MetricDerivative.Fill( NumericTraits< MeasureType >::Zero );
- this->m_PRatioArray.Fill( 0.0 );
- }
-
- // Reset marginal pdf to all zeros.
- // Assumed the size has already been set to NumberOfHistogramBins
- // in Initialize().
- for ( unsigned int j = 0; j < m_NumberOfHistogramBins; j++ ) {
- m_FixedImageMarginalPDF[j] = 0.0;
- m_MovingImageMarginalPDF[j] = 0.0;
- }
-
- // Reset the joint pdfs to zero
- m_JointPDF->FillBuffer( 0.0 );
-
-
- // Set up the parameters in the transform
- this->m_Transform->SetParameters( parameters );
-
-
- // Declare iterators for iteration over the sample container
- typename FixedImageSpatialSampleContainer::const_iterator fiter;
- typename FixedImageSpatialSampleContainer::const_iterator fend =
- m_FixedImageSamples.end();
-
- unsigned long nSamples=0;
- unsigned long nFixedImageSamples=0;
-
- for ( fiter = m_FixedImageSamples.begin(); fiter != fend; ++fiter ) {
-
- // Get moving image value
- MovingImagePointType mappedPoint;
- bool sampleOk;
- double movingImageValue;
-
-
- this->TransformPoint( nFixedImageSamples, parameters, mappedPoint,
- sampleOk, movingImageValue );
-
- if( sampleOk ) {
- ++nSamples;
-
- // Get moving image derivative at the mapped position
- ImageDerivativesType movingImageGradientValue;
- this->ComputeImageDerivatives( mappedPoint, movingImageGradientValue );
-
-
- /**
- * Compute this sample's contribution to the marginal
- * and joint distributions.
- *
- */
-
- // Determine parzen window arguments (see eqn 6 of Mattes paper [2])
- double movingImageParzenWindowTerm =
- movingImageValue / m_MovingImageBinSize - m_MovingImageNormalizedMin;
- unsigned int movingImageParzenWindowIndex =
- static_cast<unsigned int>( vcl_floor(movingImageParzenWindowTerm ) );
-
- // Make sure the extreme values are in valid bins
- if ( movingImageParzenWindowIndex < 2 ) {
- movingImageParzenWindowIndex = 2;
- } else if ( movingImageParzenWindowIndex > (m_NumberOfHistogramBins - 3) ) {
- movingImageParzenWindowIndex = m_NumberOfHistogramBins - 3;
- }
-
-
- // Since a zero-order BSpline (box car) kernel is used for
- // the fixed image marginal pdf, we need only increment the
- // fixedImageParzenWindowIndex by value of 1.0.
- m_FixedImageMarginalPDF[(*fiter).FixedImageParzenWindowIndex] +=
- static_cast<PDFValueType>( 1 );
-
- /**
- * The region of support of the parzen window determines which bins
- * of the joint PDF are effected by the pair of image values.
- * Since we are using a cubic spline for the moving image parzen
- * window, four bins are effected. The fixed image parzen window is
- * a zero-order spline (box car) and thus effects only one bin.
- *
- * The PDF is arranged so that moving image bins corresponds to the
- * zero-th (column) dimension and the fixed image bins corresponds
- * to the first (row) dimension.
- *
- */
-
- // Pointer to affected bin to be updated
- JointPDFValueType *pdfPtr = m_JointPDF->GetBufferPointer() +
- ( (*fiter).FixedImageParzenWindowIndex * m_NumberOfHistogramBins );
-
- // Move the pointer to the fist affected bin
- int pdfMovingIndex = static_cast<int>( movingImageParzenWindowIndex ) - 1;
- pdfPtr += pdfMovingIndex;
-
- for (; pdfMovingIndex <= static_cast<int>( movingImageParzenWindowIndex )
- + 2;
- pdfMovingIndex++, pdfPtr++ ) {
- // Update PDF for the current intensity pair
- double movingImageParzenWindowArg =
- static_cast<double>( pdfMovingIndex ) -
- static_cast<double>(movingImageParzenWindowTerm);
-
- *(pdfPtr) += static_cast<PDFValueType>(
- m_CubicBSplineKernel->Evaluate( movingImageParzenWindowArg ) );
-
- if( this->m_UseExplicitPDFDerivatives ) {
- // Compute the cubicBSplineDerivative for later repeated use.
- double cubicBSplineDerivativeValue =
- m_CubicBSplineDerivativeKernel->Evaluate(
- movingImageParzenWindowArg );
-
- // Compute PDF derivative contribution.
- this->ComputePDFDerivatives( nFixedImageSamples,
- pdfMovingIndex,
- movingImageGradientValue,
- cubicBSplineDerivativeValue );
- }
-
- } //end parzen windowing for loop
-
- } //end if-block check sampleOk
-
- ++nFixedImageSamples;
-
- } // end iterating over fixed image spatial sample container for loop
-
- itkDebugMacro( "Ratio of voxels mapping into moving image buffer: "
- << nSamples << " / " << m_NumberOfSpatialSamples
- << std::endl );
-
- if( nSamples < m_NumberOfSpatialSamples / 16 ) {
- itkExceptionMacro( "Too many samples map outside moving image buffer: "
- << nSamples << " / " << m_NumberOfSpatialSamples
- << std::endl );
- }
-
- this->m_NumberOfPixelsCounted = nSamples;
-
- /**
- * Normalize the PDFs, compute moving image marginal PDF
- *
- */
- typedef ImageRegionIterator<JointPDFType> JointPDFIteratorType;
- JointPDFIteratorType jointPDFIterator ( m_JointPDF,
- m_JointPDF->GetBufferedRegion() );
-
- jointPDFIterator.GoToBegin();
-
-
- // Compute joint PDF normalization factor
- // (to ensure joint PDF sum adds to 1.0)
- double jointPDFSum = 0.0;
-
- while( !jointPDFIterator.IsAtEnd() ) {
- jointPDFSum += jointPDFIterator.Get();
- ++jointPDFIterator;
- }
-
- if ( jointPDFSum == 0.0 ) {
- itkExceptionMacro( "Joint PDF summed to zero" );
- }
-
-
- // Normalize the PDF bins
- jointPDFIterator.GoToEnd();
- while( !jointPDFIterator.IsAtBegin() ) {
- --jointPDFIterator;
- jointPDFIterator.Value() /= static_cast<PDFValueType>( jointPDFSum );
- }
-
-
- // Normalize the fixed image marginal PDF
- double fixedPDFSum = 0.0;
- for( unsigned int bin = 0; bin < m_NumberOfHistogramBins; bin++ ) {
- fixedPDFSum += m_FixedImageMarginalPDF[bin];
- }
-
- if ( fixedPDFSum == 0.0 ) {
- itkExceptionMacro( "Fixed image marginal PDF summed to zero" );
- }
-
- for( unsigned int bin=0; bin < m_NumberOfHistogramBins; bin++ ) {
- m_FixedImageMarginalPDF[bin] /= static_cast<PDFValueType>( fixedPDFSum );
- }
-
-
- // Compute moving image marginal PDF by summing over fixed image bins.
- typedef ImageLinearIteratorWithIndex<JointPDFType> JointPDFLinearIterator;
- JointPDFLinearIterator linearIter(
- m_JointPDF, m_JointPDF->GetBufferedRegion() );
-
- linearIter.SetDirection( 1 );
- linearIter.GoToBegin();
- unsigned int movingIndex1 = 0;
-
- while( !linearIter.IsAtEnd() ) {
-
- double sum = 0.0;
-
- while( !linearIter.IsAtEndOfLine() ) {
- sum += linearIter.Get();
- ++linearIter;
- }
-
- m_MovingImageMarginalPDF[movingIndex1] = static_cast<PDFValueType>(sum);
-
- linearIter.NextLine();
- ++movingIndex1;
-
- }
-
- double nFactor = 1.0 / ( m_MovingImageBinSize
- * static_cast<double>( nSamples ) );
-
- if( this->m_UseExplicitPDFDerivatives ) {
- // Normalize the joint PDF derivatives by the test image binsize and nSamples
- typedef ImageRegionIterator<JointPDFDerivativesType>
- JointPDFDerivativesIteratorType;
- JointPDFDerivativesIteratorType jointPDFDerivativesIterator (
- m_JointPDFDerivatives,
- m_JointPDFDerivatives->GetBufferedRegion()
- );
-
- jointPDFDerivativesIterator.GoToBegin();
-
- while( !jointPDFDerivativesIterator.IsAtEnd() ) {
- jointPDFDerivativesIterator.Value() *= nFactor;
- ++jointPDFDerivativesIterator;
- }
- }
-
- /**
- * Compute the metric by double summation over histogram.
- */
-
- // Setup pointer to point to the first bin
- JointPDFValueType * jointPDFPtr = m_JointPDF->GetBufferPointer();
-
- // Initialize sum to zero
- double sum = 0.0;
-
- for( unsigned int fixedIndex = 0;
- fixedIndex < m_NumberOfHistogramBins;
- ++fixedIndex ) {
- double fixedImagePDFValue = m_FixedImageMarginalPDF[fixedIndex];
-
- for( unsigned int movingIndex = 0; movingIndex < m_NumberOfHistogramBins;
- ++movingIndex, jointPDFPtr++ ) {
- double movingImagePDFValue = m_MovingImageMarginalPDF[movingIndex];
- double jointPDFValue = *(jointPDFPtr);
-
- // check for non-zero bin contribution
- if( jointPDFValue > 1e-16 && movingImagePDFValue > 1e-16 ) {
-
- double pRatio = vcl_log(jointPDFValue / movingImagePDFValue );
-
- if( fixedImagePDFValue > 1e-16) {
- sum += jointPDFValue * ( pRatio - vcl_log(fixedImagePDFValue ) );
- }
-
- if( this->m_UseExplicitPDFDerivatives ) {
- // move joint pdf derivative pointer to the right position
- JointPDFValueType * derivPtr = m_JointPDFDerivatives->GetBufferPointer()
- + ( fixedIndex * m_JointPDFDerivatives->GetOffsetTable()[2] )
- + ( movingIndex * m_JointPDFDerivatives->GetOffsetTable()[1] );
-
- for( unsigned int parameter=0; parameter < m_NumberOfParameters; ++parameter, derivPtr++ ) {
- // Ref: eqn 23 of Thevenaz & Unser paper [3]
- derivative[parameter] -= (*derivPtr) * pRatio;
- } // end for-loop over parameters
- } else {
- this->m_PRatioArray[fixedIndex][movingIndex] = pRatio * nFactor;
- }
- } // end if-block to check non-zero bin contribution
- } // end for-loop over moving index
- } // end for-loop over fixed index
-
- if( !(this->m_UseExplicitPDFDerivatives ) ) {
- // Second pass: This one is done for accumulating the contributions
- // to the derivative array.
-
- nFixedImageSamples = 0;
-
- for ( fiter = m_FixedImageSamples.begin(); fiter != fend; ++fiter ) {
-
- // Get moving image value
- MovingImagePointType mappedPoint;
- bool sampleOk;
- double movingImageValue;
-
- this->TransformPoint( nFixedImageSamples, parameters, mappedPoint,
- sampleOk, movingImageValue );
-
- if( sampleOk ) {
- // Get moving image derivative at the mapped position
- ImageDerivativesType movingImageGradientValue;
- this->ComputeImageDerivatives( mappedPoint, movingImageGradientValue );
-
-
- /**
- * Compute this sample's contribution to the marginal
- * and joint distributions.
- *
- */
-
- // Determine parzen window arguments (see eqn 6 of Mattes paper [2]).
- double movingImageParzenWindowTerm =
- movingImageValue / m_MovingImageBinSize - m_MovingImageNormalizedMin;
- unsigned int movingImageParzenWindowIndex =
- static_cast<unsigned int>( vcl_floor(movingImageParzenWindowTerm ) );
-
- // Make sure the extreme values are in valid bins
- if ( movingImageParzenWindowIndex < 2 ) {
- movingImageParzenWindowIndex = 2;
- } else if ( movingImageParzenWindowIndex > (m_NumberOfHistogramBins - 3) ) {
- movingImageParzenWindowIndex = m_NumberOfHistogramBins - 3;
- }
-
-
- // Move the pointer to the fist affected bin
- int pdfMovingIndex = static_cast<int>( movingImageParzenWindowIndex ) - 1;
-
- for (; pdfMovingIndex <= static_cast<int>( movingImageParzenWindowIndex )
- + 2;
- pdfMovingIndex++ ) {
-
- // Update PDF for the current intensity pair
- double movingImageParzenWindowArg =
- static_cast<double>( pdfMovingIndex ) -
- static_cast<double>(movingImageParzenWindowTerm);
-
- // Compute the cubicBSplineDerivative for later repeated use.
- double cubicBSplineDerivativeValue =
- m_CubicBSplineDerivativeKernel->Evaluate(
- movingImageParzenWindowArg );
-
- // Compute PDF derivative contribution.
- this->ComputePDFDerivatives( nFixedImageSamples,
- pdfMovingIndex,
- movingImageGradientValue,
- cubicBSplineDerivativeValue );
-
-
- } //end parzen windowing for loop
-
- } //end if-block check sampleOk
-
- ++nFixedImageSamples;
-
- } // end iterating over fixed image spatial sample container for loop
-
-
- derivative = this->m_MetricDerivative;
- }
-
- value = static_cast<MeasureType>( -1.0 * sum );
-}
-
-
-/**
- * Get the match measure derivative
- */
-template < class TFixedImage, class TMovingImage >
-void
-MattesMutualInformationImageToImageMetricFor3DBLUTFFD<TFixedImage,TMovingImage>
-::GetDerivative( const ParametersType& parameters,
- DerivativeType & derivative ) const
-{
- MeasureType value;
- // call the combined version
- this->GetValueAndDerivative( parameters, value, derivative );
-}
-
-
-/**
- * Compute image derivatives using a central difference function
- * if we are not using a BSplineInterpolator, which includes
- * derivatives.
- */
-template < class TFixedImage, class TMovingImage >
-void
-MattesMutualInformationImageToImageMetricFor3DBLUTFFD<TFixedImage,TMovingImage>
-::ComputeImageDerivatives(
- const MovingImagePointType& mappedPoint,
- ImageDerivativesType& gradient ) const
-{
-
- if( m_InterpolatorIsBSpline ) {
- // Computed moving image gradient using derivative BSpline kernel.
- gradient = m_BSplineInterpolator->EvaluateDerivative( mappedPoint );
- } else {
- // For all generic interpolator use central differencing.
- gradient = m_DerivativeCalculator->Evaluate( mappedPoint );
- }
-
-}
-
-
-/**
- * Transform a point from FixedImage domain to MovingImage domain.
- * This function also checks if mapped point is within support region.
- */
-template < class TFixedImage, class TMovingImage >
-void
-MattesMutualInformationImageToImageMetricFor3DBLUTFFD<TFixedImage,TMovingImage>
-::TransformPoint(
- unsigned int sampleNumber,
- const ParametersType& parameters,
- MovingImagePointType& mappedPoint,
- bool& sampleOk,
- double& movingImageValue ) const
-{
-
- if ( !m_TransformIsBSpline ) {
- // Use generic transform to compute mapped position
- mappedPoint = this->m_Transform->TransformPoint(
- m_FixedImageSamples[sampleNumber].FixedImagePointValue );
-
- // Check if mapped point inside image buffer
- sampleOk = this->m_Interpolator->IsInsideBuffer( mappedPoint );
- } else {
-
- if( this->m_UseCachingOfBSplineWeights ) {
- // If the transform is BSplineDeformable, we can use the precomputed
- // weights and indices to obtained the mapped position
- //
- const WeightsValueType * weights =
- m_BSplineTransformWeightsArray[sampleNumber];
- const IndexValueType * indices =
- m_BSplineTransformIndicesArray[sampleNumber];
- mappedPoint.Fill( 0.0 );
-
- if ( m_WithinSupportRegionArray[sampleNumber] ) {
- for ( unsigned int k = 0; k < m_NumBSplineWeights; k++ ) {
- for ( unsigned int j = 0; j < FixedImageDimension; j++ ) {
- mappedPoint[j] += weights[k] *
- parameters[ indices[k] + m_ParametersOffset[j] ];
- }
- }
- }
-
- for( unsigned int j = 0; j < FixedImageDimension; j++ ) {
- mappedPoint[j] += m_PreTransformPointsArray[sampleNumber][j];
- }
-
- // Check if mapped point inside image buffer
- sampleOk = this->m_Interpolator->IsInsideBuffer( mappedPoint );
-
- // Check if mapped point is within the support region of a grid point.
- // This is neccessary for computing the metric gradient
- sampleOk = sampleOk && m_WithinSupportRegionArray[sampleNumber];
- } else {
- // If not caching values, we invoke the Transform to recompute the
- // mapping of the point.
- this->m_BSplineTransform->TransformPoint(
- this->m_FixedImageSamples[sampleNumber].FixedImagePointValue,
- mappedPoint, this->m_Weights, this->m_Indices, sampleOk);
-
- // Check if mapped point inside image buffer
- sampleOk = sampleOk && this->m_Interpolator->IsInsideBuffer( mappedPoint );
- }
-
- }
-
- // If user provided a mask over the Moving image
- if ( this->m_MovingImageMask ) {
- // Check if mapped point is within the support region of the moving image
- // mask
- sampleOk = sampleOk && this->m_MovingImageMask->IsInside( mappedPoint );
- }
-
-
- if ( sampleOk ) {
- movingImageValue = this->m_Interpolator->Evaluate( mappedPoint );
-
- if ( movingImageValue < m_MovingImageTrueMin ||
- movingImageValue > m_MovingImageTrueMax ) {
- // need to throw out this sample as it will not fall into a valid bin
- sampleOk = false;
- }
- }
-}
-
-
-/**
- * Compute PDF derivatives contribution for each parameter
- */
-template < class TFixedImage, class TMovingImage >
-void
-MattesMutualInformationImageToImageMetricFor3DBLUTFFD<TFixedImage,TMovingImage>
-::ComputePDFDerivatives(
- unsigned int sampleNumber,
- int pdfMovingIndex,
- const ImageDerivativesType& movingImageGradientValue,
- double cubicBSplineDerivativeValue ) const
-{
-
- const int pdfFixedIndex =
- m_FixedImageSamples[sampleNumber].FixedImageParzenWindowIndex;
-
- JointPDFValueType * derivPtr = NULL;
- double precomputedWeight = 0.0;
-
- if( this->m_UseExplicitPDFDerivatives ) {
- // Update bins in the PDF derivatives for the current intensity pair
- derivPtr = m_JointPDFDerivatives->GetBufferPointer() +
- ( pdfFixedIndex * m_JointPDFDerivatives->GetOffsetTable()[2] ) +
- ( pdfMovingIndex * m_JointPDFDerivatives->GetOffsetTable()[1] );
- } else {
- // Recover the precomputed weight for this specific PDF bin
- precomputedWeight = this->m_PRatioArray[pdfFixedIndex][pdfMovingIndex];
- }
-
- if( !m_TransformIsBSpline ) {
-
- /**
- * Generic version which works for all transforms.
- */
-
- // Compute the transform Jacobian.
- typedef typename TransformType::JacobianType JacobianType;
-#if ITK_VERSION_MAJOR >= 4
- JacobianType jacobian;
- this->m_Transform->ComputeJacobianWithRespectToParameters( m_FixedImageSamples[sampleNumber].FixedImagePointValue, jacobian );
-#else
- const JacobianType & jacobian =
- this->m_Transform->GetJacobian( m_FixedImageSamples[sampleNumber].FixedImagePointValue );
-#endif
-
- for ( unsigned int mu = 0; mu < m_NumberOfParameters; mu++ ) {
- double innerProduct = 0.0;
- for ( unsigned int dim = 0; dim < FixedImageDimension; dim++ ) {
- innerProduct += jacobian[dim][mu] * movingImageGradientValue[dim];
- }
-
- const double derivativeContribution = innerProduct * cubicBSplineDerivativeValue;
-
- if( this->m_UseExplicitPDFDerivatives ) {
- *(derivPtr) -= derivativeContribution;
- ++derivPtr;
- } else {
- this->m_MetricDerivative[mu] += precomputedWeight * derivativeContribution;
- }
- }
-
- } else {
- const WeightsValueType * weights = NULL;
- const IndexValueType * indices = NULL;
-
- if( this->m_UseCachingOfBSplineWeights ) {
- /**
- * If the transform is of type BSplineDeformableTransform,
- * we can obtain a speed up by only processing the affected parameters.
- * Note that these pointers are just pointing to pre-allocated rows
- * of the caching arrays. There is therefore, no need to free this
- * memory.
- */
- weights = m_BSplineTransformWeightsArray[sampleNumber];
- indices = m_BSplineTransformIndicesArray[sampleNumber];
- } else {
-#if ITK_VERSION_MAJOR >= 4
- m_BSplineTransform->ComputeJacobianFromBSplineWeightsWithRespectToPosition(
- m_FixedImageSamples[sampleNumber].FixedImagePointValue, m_Weights, m_Indices );
-#else
- m_BSplineTransform->GetJacobian(
- m_FixedImageSamples[sampleNumber].FixedImagePointValue, m_Weights, m_Indices );
-#endif
- }
-
- for( unsigned int dim = 0; dim < FixedImageDimension; dim++ ) {
-
- double innerProduct;
- int parameterIndex;
-
- for( unsigned int mu = 0; mu < m_NumBSplineWeights; mu++ ) {
-
- /* The array weights contains the Jacobian values in a 1-D array
- * (because for each parameter the Jacobian is non-zero in only 1 of the
- * possible dimensions) which is multiplied by the moving image
- * gradient. */
- if( this->m_UseCachingOfBSplineWeights ) {
- innerProduct = movingImageGradientValue[dim] * weights[mu];
- parameterIndex = indices[mu] + m_ParametersOffset[dim];
- } else {
- innerProduct = movingImageGradientValue[dim] * this->m_Weights[mu];
- parameterIndex = this->m_Indices[mu] + this->m_ParametersOffset[dim];
- }
-
- const double derivativeContribution = innerProduct * cubicBSplineDerivativeValue;
-
- if( this->m_UseExplicitPDFDerivatives ) {
- JointPDFValueType * ptr = derivPtr + parameterIndex;
- *(ptr) -= derivativeContribution;
- } else {
- this->m_MetricDerivative[parameterIndex] += precomputedWeight * derivativeContribution;
- }
-
- } //end mu for loop
- } //end dim for loop
-
- } // end if-block transform is BSpline
-
-}
-
-
-// Method to reinitialize the seed of the random number generator
-template < class TFixedImage, class TMovingImage > void
-MattesMutualInformationImageToImageMetricFor3DBLUTFFD<TFixedImage,TMovingImage>
-::ReinitializeSeed()
-{
- Statistics::MersenneTwisterRandomVariateGenerator::GetInstance()->SetSeed();
-}
-
-// Method to reinitialize the seed of the random number generator
-template < class TFixedImage, class TMovingImage > void
-MattesMutualInformationImageToImageMetricFor3DBLUTFFD<TFixedImage,TMovingImage>
-::ReinitializeSeed(int seed)
-{
- Statistics::MersenneTwisterRandomVariateGenerator::GetInstance()->SetSeed(
- seed);
-}
-
-
-/**
- * Cache pre-transformed points, weights and indices.
- * This method is only called if the flag UseCachingOfBSplineWeights is ON.
- */
-template < class TFixedImage, class TMovingImage >
-void
-MattesMutualInformationImageToImageMetricFor3DBLUTFFD<TFixedImage,TMovingImage>
-::PreComputeTransformValues()
-{
- // Create all zero dummy transform parameters
- ParametersType dummyParameters( this->m_Transform->GetNumberOfParameters() );
- dummyParameters.Fill( 0.0 );
- this->m_Transform->SetParameters( dummyParameters );
-
- // Cycle through each sampled fixed image point
- BSplineTransformWeightsType weights( m_NumBSplineWeights );
- BSplineTransformIndexArrayType indices( m_NumBSplineWeights );
- bool valid;
- MovingImagePointType mappedPoint;
-
- // Declare iterators for iteration over the sample container
- typename FixedImageSpatialSampleContainer::const_iterator fiter;
- typename FixedImageSpatialSampleContainer::const_iterator fend =
- m_FixedImageSamples.end();
- unsigned long counter = 0;
-
- for( fiter = m_FixedImageSamples.begin(); fiter != fend; ++fiter, counter++ ) {
- m_BSplineTransform->TransformPoint(
- m_FixedImageSamples[counter].FixedImagePointValue,
- mappedPoint, weights, indices, valid );
-
- for( unsigned long k = 0; k < m_NumBSplineWeights; k++ ) {
- m_BSplineTransformWeightsArray[counter][k] = weights[k];
- m_BSplineTransformIndicesArray[counter][k] = indices[k];
- }
-
- m_PreTransformPointsArray[counter] = mappedPoint;
- m_WithinSupportRegionArray[counter] = valid;
-
- }
-
-}
-
-
-} // end namespace itk
-
-
-#endif
-
#endif