/*========================================================================= * * Copyright Insight Software Consortium * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0.txt * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * *=========================================================================*/ #ifndef itkESMDemonsRegistrationFunction_h #define itkESMDemonsRegistrationFunction_h #include "itkPDEDeformableRegistrationFunction.h" #include "itkCentralDifferenceImageFunction.h" #include "itkWarpImageFilter.h" namespace itk { /** * \class ESMDemonsRegistrationFunction * * \brief Fast implementation of the symmetric demons registration force * * This class provides a substantially faster implementation of the * symmetric demons registration force. Speed is improved by keeping * a deformed copy of the moving image for gradient evaluation. * * Symmetric forces simply means using the mean of the gradient * of the fixed image and the gradient of the warped moving * image. * * Note that this class also enables the use of fixed, mapped moving * and warped moving images forces by using a call to SetUseGradientType * * The moving image should not be saturated. We indeed use * NumericTraits::Max() as a special value. * * \author Tom Vercauteren, INRIA & Mauna Kea Technologies * * This implementation was taken from the Insight Journal paper: * https://hdl.handle.net/1926/510 * * \sa SymmetricForcesDemonsRegistrationFunction * \sa SymmetricForcesDemonsRegistrationFilter * \sa DemonsRegistrationFilter * \sa DemonsRegistrationFunction * \ingroup FiniteDifferenceFunctions * * \ingroup ITKPDEDeformableRegistration */ template< typename TFixedImage, typename TMovingImage, typename TDisplacementField > class ITK_TEMPLATE_EXPORT ESMDemonsRegistrationFunction: public PDEDeformableRegistrationFunction< TFixedImage, TMovingImage, TDisplacementField > { public: /** Standard class typedefs. */ typedef ESMDemonsRegistrationFunction Self; typedef PDEDeformableRegistrationFunction< TFixedImage, TMovingImage, TDisplacementField > Superclass; typedef SmartPointer< Self > Pointer; typedef SmartPointer< const Self > ConstPointer; /** Method for creation through the object factory. */ itkNewMacro(Self); /** Run-time type information (and related methods). */ itkTypeMacro(ESMDemonsRegistrationFunction, PDEDeformableRegistrationFunction); /** MovingImage image type. */ typedef typename Superclass::MovingImageType MovingImageType; typedef typename Superclass::MovingImagePointer MovingImagePointer; typedef typename MovingImageType::PixelType MovingPixelType; /** FixedImage image type. */ typedef typename Superclass::FixedImageType FixedImageType; typedef typename Superclass::FixedImagePointer FixedImagePointer; typedef typename FixedImageType::IndexType IndexType; typedef typename FixedImageType::SizeType SizeType; typedef typename FixedImageType::SpacingType SpacingType; typedef typename FixedImageType::DirectionType DirectionType; /** Deformation field type. */ typedef typename Superclass::DisplacementFieldType DisplacementFieldType; typedef typename Superclass::DisplacementFieldTypePointer DisplacementFieldTypePointer; /** Inherit some enums from the superclass. */ itkStaticConstMacro(ImageDimension, unsigned int, Superclass::ImageDimension); /** Inherit some enums from the superclass. */ typedef typename Superclass::PixelType PixelType; typedef typename Superclass::RadiusType RadiusType; typedef typename Superclass::NeighborhoodType NeighborhoodType; typedef typename Superclass::FloatOffsetType FloatOffsetType; typedef typename Superclass::TimeStepType TimeStepType; /** Interpolator type. */ typedef double CoordRepType; typedef InterpolateImageFunction< MovingImageType, CoordRepType > InterpolatorType; typedef typename InterpolatorType::Pointer InterpolatorPointer; typedef typename InterpolatorType::PointType PointType; typedef LinearInterpolateImageFunction< MovingImageType, CoordRepType > DefaultInterpolatorType; /** Warper type */ typedef WarpImageFilter< MovingImageType, MovingImageType, DisplacementFieldType > WarperType; typedef typename WarperType::Pointer WarperPointer; /** Covariant vector type. */ typedef CovariantVector< double, itkGetStaticConstMacro(ImageDimension) > CovariantVectorType; /** Fixed image gradient calculator type. */ typedef CentralDifferenceImageFunction< FixedImageType > GradientCalculatorType; typedef typename GradientCalculatorType::Pointer GradientCalculatorPointer; /** Moving image gradient (unwarped) calculator type. */ typedef CentralDifferenceImageFunction< MovingImageType, CoordRepType > MovingImageGradientCalculatorType; typedef typename MovingImageGradientCalculatorType::Pointer MovingImageGradientCalculatorPointer; /** Set the moving image interpolator. */ void SetMovingImageInterpolator(InterpolatorType *ptr) { m_MovingImageInterpolator = ptr; m_MovingImageWarper->SetInterpolator(ptr); } /** Get the moving image interpolator. */ InterpolatorType * GetMovingImageInterpolator(void) { return m_MovingImageInterpolator; } /** This class uses a constant timestep of 1. */ virtual TimeStepType ComputeGlobalTimeStep( void *itkNotUsed(GlobalData) ) const ITK_OVERRIDE { return m_TimeStep; } /** Return a pointer to a global data structure that is passed to * this object from the solver at each calculation. */ virtual void * GetGlobalDataPointer() const ITK_OVERRIDE { GlobalDataStruct *global = new GlobalDataStruct(); global->m_SumOfSquaredDifference = 0.0; global->m_NumberOfPixelsProcessed = 0L; global->m_SumOfSquaredChange = 0; return global; } /** Release memory for global data structure. */ virtual void ReleaseGlobalDataPointer(void *GlobalData) const ITK_OVERRIDE; /** Set the object's state before each iteration. */ virtual void InitializeIteration() ITK_OVERRIDE; /** This method is called by a finite difference solver image filter at * each pixel that does not lie on a data set boundary */ virtual PixelType ComputeUpdate( const NeighborhoodType & neighborhood, void *globalData, const FloatOffsetType & offset = FloatOffsetType(0.0) ) ITK_OVERRIDE; /** Get the metric value. The metric value is the mean square difference * in intensity between the fixed image and transforming moving image * computed over the the overlapping region between the two images. */ virtual double GetMetric() const { return m_Metric; } /** Get the rms change in deformation field. */ virtual const double & GetRMSChange() const { return m_RMSChange; } /** Set/Get the threshold below which the absolute difference of * intensity yields a match. When the intensities match between a * moving and fixed image pixel, the update vector (for that * iteration) will be the zero vector. Default is 0.001. */ virtual void SetIntensityDifferenceThreshold(double); virtual double GetIntensityDifferenceThreshold() const; /** Set/Get the maximum update step length. In Thirion this is 0.5. * Setting it to 0 implies no restriction (beware of numerical * instability in this case. */ virtual void SetMaximumUpdateStepLength(double sm) { this->m_MaximumUpdateStepLength = sm; } virtual double GetMaximumUpdateStepLength() const { return this->m_MaximumUpdateStepLength; } /** Type of available image forces */ enum GradientType { Symmetric = 0, Fixed = 1, WarpedMoving = 2, MappedMoving = 3 }; /** Set/Get the type of used image forces */ virtual void SetUseGradientType(GradientType gtype) { m_UseGradientType = gtype; } virtual GradientType GetUseGradientType() const { return m_UseGradientType; } protected: ESMDemonsRegistrationFunction(); ~ESMDemonsRegistrationFunction() ITK_OVERRIDE {} void PrintSelf(std::ostream & os, Indent indent) const ITK_OVERRIDE; /** FixedImage image neighborhood iterator type. */ typedef ConstNeighborhoodIterator< FixedImageType > FixedImageNeighborhoodIteratorType; /** A global data type for this class of equation. Used to store * iterators for the fixed image. */ struct GlobalDataStruct { double m_SumOfSquaredDifference; SizeValueType m_NumberOfPixelsProcessed; double m_SumOfSquaredChange; }; private: ITK_DISALLOW_COPY_AND_ASSIGN(ESMDemonsRegistrationFunction); /** Cache fixed image information. */ PointType m_FixedImageOrigin; SpacingType m_FixedImageSpacing; DirectionType m_FixedImageDirection; double m_Normalizer; /** Function to compute derivatives of the fixed image. */ GradientCalculatorPointer m_FixedImageGradientCalculator; /** Function to compute derivatives of the moving image (unwarped). */ MovingImageGradientCalculatorPointer m_MappedMovingImageGradientCalculator; GradientType m_UseGradientType; /** Function to interpolate the moving image. */ InterpolatorPointer m_MovingImageInterpolator; /** Filter to warp moving image for fast gradient computation. */ WarperPointer m_MovingImageWarper; MovingImageType *m_MovingImageWarperOutput; /** The global timestep. */ TimeStepType m_TimeStep; /** Threshold below which the denominator term is considered zero. */ double m_DenominatorThreshold; /** Threshold below which two intensity value are assumed to match. */ double m_IntensityDifferenceThreshold; /** Maximum update step length in pixels (default is 0.5 as in Thirion). */ double m_MaximumUpdateStepLength; /** The metric value is the mean square difference in intensity between * the fixed image and transforming moving image computed over the * the overlapping region between the two images. */ mutable double m_Metric; mutable double m_SumOfSquaredDifference; mutable SizeValueType m_NumberOfPixelsProcessed; mutable double m_RMSChange; mutable double m_SumOfSquaredChange; /** Mutex lock to protect modification to metric. */ mutable SimpleFastMutexLock m_MetricCalculationLock; }; } // end namespace itk #ifndef ITK_MANUAL_INSTANTIATION #include "itkESMDemonsRegistrationFunction.hxx" #endif #endif