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itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage > Class Template Reference

This class implements a finite difference partial differential equation solver for evolving surfaces embedded in volumes as level-sets. More...

#include <itkSparseFieldLevelSetImageFilter.h>

Inheritance diagram for itk::SparseFieldLevelSetImageFilter:

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List of all members.

Public Types

typedef SparseFieldLevelSetImageFilter Self
typedef FiniteDifferenceImageFilter<
TInputImage, TOutputImage > 		Superclass
typedef SmartPointer< Self > Pointer
typedef SmartPointer< const
Self > 		ConstPointer
typedef Superclass::TimeStepType TimeStepType
typedef TInputImage InputImageType
typedef TOutputImage OutputImageType
typedef OutputImageType::IndexType IndexType
typedef OutputImageType::ValueType ValueType
typedef SparseFieldLevelSetNode<
IndexType > 		LayerNodeType
typedef SparseFieldLayer<
LayerNodeType > 		LayerType
typedef LayerType::Pointer LayerPointerType
typedef std::vector< LayerPointerType > LayerListType
typedef char StatusType
typedef Image< StatusType,
itkGetStaticConstMacro(ImageDimension) 		StatusImageType )
typedef ObjectStore< LayerNodeType > LayerNodeStorageType
typedef std::vector< ValueType > UpdateBufferType

Public Methods

virtual const char * GetClassName () const
 itkStaticConstMacro (ImageDimension, unsigned int, TOutputImage::ImageDimension)
virtual ValueType GetRMSChange ()
virtual void SetNumberOfLayers (unsigned int _arg)
virtual unsigned int GetNumberOfLayers ()
virtual void SetIsoSurfaceValue (ValueType _arg)
virtual ValueType GetIsoSurfaceValue ()

Static Public Methods

Pointer New ()

Protected Methods

 SparseFieldLevelSetImageFilter ()
 ~SparseFieldLevelSetImageFilter ()
virtual void PrintSelf (std::ostream &os, Indent indent) const
virtual ValueType CalculateUpdateValue (const IndexType &idx, const TimeStepType &dt, const ValueType &value, const ValueType &change)
virtual void PostProcessOutput ()
virtual void InitializeBackgroundPixels ()
void Initialize ()
void CopyInputToOutput ()
void AllocateUpdateBuffer ()
void ApplyUpdate (TimeStepType dt)
TimeStepType CalculateChange ()
void ConstructLayer (StatusType from, StatusType to)
void ConstructActiveLayer ()
void InitializeActiveLayerValues ()
void PropagateLayerValues (StatusType from, StatusType to, StatusType promote, int InOrOut)
void PropagateAllLayerValues ()
void UpdateActiveLayerValues (TimeStepType dt, LayerType *StatusUpList, LayerType *StatusDownList)
void ProcessStatusList (LayerType *InputList, LayerType *OutputList, StatusType ChangeToStatus, StatusType SearchForStatus)
void ProcessOutsideList (LayerType *OutsideList, StatusType ChangeToStatus)

Protected Attributes

SparseFieldCityBlockNeighborList<
SmartNeighborhoodIterator<
OutputImageType > > 		m_NeighborList
OutputImageType::Pointer m_ShiftedImage
LayerListType m_Layers
unsigned int m_NumberOfLayers
StatusImageType::Pointer m_StatusImage
LayerNodeStorageType::Pointer m_LayerNodeStore
ValueType m_IsoSurfaceValue
UpdateBufferType m_UpdateBuffer
ValueType m_RMSChange

Static Protected Attributes

double m_ConstantGradientValue
ValueType m_ValueOne
ValueType m_ValueZero
StatusType m_StatusChanging
StatusType m_StatusActiveChangingUp
StatusType m_StatusActiveChangingDown
StatusType m_StatusNull

Detailed Description

template<class TInputImage, class TOutputImage>
class itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >

This class implements a finite difference partial differential equation solver for evolving surfaces embedded in volumes as level-sets.

The ``sparse field'' approach to the level-set model is a logical extension of the classical narrow band technique, which seeks to minimize computational effort by restricting calculations to those pixels in a region of interest around the moving surface (the -level curve). The sparse field method uses a narrow band that is exactly the width needed to calculate changes on the level curve for the next time step. Because the band of grid points under consideration is so sparse, this approach has several advantages: the algorithm does exactly the number of calculations needed to determine the next position of the -level curve, and the distance transform around the level curve can be recomputed at each iteration.

The sparse field algorithm works by constructing a linked list of indicies that are adjacent to the -level set. These indicies are called the ``active set''. The values at these active set indicies define the position of the -level curve. The active set indicies are shifted to follow the distance transform embedding of the -level curve as their values move in and out of a fixed numerical range about . In this way, the active set is maintained as only those pixels adjacent to the evolving surface. Calculations are then done only at indicies contained in the active set.

The city-block neighborhoods of the active set indicies are maintained as separate lists called ``layers''. At each iteration, the values at the layers are reinitialized as the distance transform from the active set. The number of layers can be adjusted according to the footprint needed for the calculations on the level curve.

Briefly, the sparse field solver algorithm is as follows:

1. For each active layer index : Compute the change at , the grid point in the embedding, based on local geometry and external forces and using a stable numerical scheme.

2. For each active layer index , add the change to the grid point value and redefine the active set indicies and those of its layers based on any value changes which have moved outside of the numerical range allowed for the active set.

3. Starting with the first layers adjacent to the active set and moving outwards, reconstruct the distance transform by setting values in the layers according to their neighbors. At the very outer layers, add or remove indicies which have come into or moved out of the sparse field.

HOW TO USE THIS CLASS
Typically, this class should be subclassed with additional functionality for specific applications. It is possible, however to use this solver as a filter directly by instantiating it and supplying it with an appropriate LevelSetFunction object via the SetDifferenceFunction method. See the subclasses and their associated documentation for more information on using this class. Also see the FiniteDifferenceImageFilter documentation for a general overview of this class of solvers.
INPUTS
This filter takes an itk::Image as input. The appropriate type of input image is entirely determined by the application. As a rule, however, the input type is immediately converted to the output type before processing. This is because the input is not assumed to be a real value type and must be converted to signed, real values for the calculations. The input values will also be shifted by the isosurface value so that the algorithm only needs to consider the zero level set.
OUTPUTS
The output of the filter is the distance transform embedding of the isosurface as the zero level set. Values outside the surface will be negative and values inside the surface will be positive. The distance transform only holds for those indicies in layers around the active layer. Elsewhere, the values are a fixed positive or negative that is one greater than the layer of greatest magnitude. In other words, if there are three layers, then inside values increase only to 4.0 and outside values only to -4.0.
PARAMETERS
The NumberOfLayers parameter controls the number of layers inside and outside of the active set (see description above). The sparse field will contain 2*NumberOfLayers+1 lists of indices: the active set and city block neighbors inside and outside the active set. It is important to specify enough layers to cover the footprint of your calculations. Curvature calculations in three dimensions, for example, require 3 layers. In two dimensions, a minimum of 2 layers is probably required. Higher order derivatives and other geometrical measures may require more layers. If too few layers are specified, then the calculations will pull values from the background, which may consist of arbitrary or random values.

The IsoSurfaceValue indicates which value in the input represents the interface of interest. By default, this value is zero. When the solver initializes, it will subtract the IsoSurfaceValue from all values, in the input, shifting the isosurface of interest to zero in the output.

IMPORTANT!
Read the documentation for FiniteDifferenceImageFilter before attempting to use this filter. The solver requires that you specify a FiniteDifferenceFunction to use for calculations. This is set using the method SetDifferenceFunction in the parent class.
REFERENCES
Whitaker, Ross. A Level-Set Approach to 3D Reconstruction from Range Data. International Journal of Computer Vision. V. 29 No. 3, 203-231. 1998.

Sethian, J.A. Level Set Methods. Cambridge University Press. 1996.

Definition at line 220 of file itkSparseFieldLevelSetImageFilter.h.

Member Typedef Documentation

template<class TInputImage, class TOutputImage>
typedef SmartPointer<const Self> itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::ConstPointer
 

Reimplemented from itk::ImageToImageFilter< TInputImage, TOutputImage >.

Reimplemented in itk::AntiAliasBinaryImageFilter< TInputImage, TOutputImage >, itk::LaplacianSegmentationLevelSetImageFilter< TInputImage, TOutputImage >, itk::SegmentationLevelSetImageFilter< TInputImage, TOutputImage >, and itk::ThresholdSegmentationLevelSetImageFilter< TInputImage, TOutputImage >.

Definition at line 229 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
typedef OutputImageType::IndexType itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::IndexType
 

Reimplemented in itk::AntiAliasBinaryImageFilter< TInputImage, TOutputImage >, and itk::SegmentationLevelSetImageFilter< TInputImage, TOutputImage >.

Definition at line 243 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
typedef TInputImage itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::InputImageType
 

Information derived from the image types.

Reimplemented from itk::FiniteDifferenceImageFilter< TInputImage, TOutputImage >.

Reimplemented in itk::AntiAliasBinaryImageFilter< TInputImage, TOutputImage >, and itk::SegmentationLevelSetImageFilter< TInputImage, TOutputImage >.

Definition at line 241 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
typedef std::vector<LayerPointerType> itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::LayerListType
 

A type for a list of LayerPointerTypes

Definition at line 259 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
typedef ObjectStore<LayerNodeType> itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::LayerNodeStorageType
 

Memory pre-allocator used to manage layer nodes in a multi-threaded environment.

Definition at line 271 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
typedef SparseFieldLevelSetNode<IndexType> itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::LayerNodeType
 

Node type used in sparse field layer lists.

Definition at line 252 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
typedef LayerType::Pointer itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::LayerPointerType
 

Definition at line 256 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
typedef SparseFieldLayer<LayerNodeType> itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::LayerType
 

A list type used in the algorithm.

Definition at line 255 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
typedef TOutputImage itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::OutputImageType
 

Some convenient typedefs.

Reimplemented from itk::FiniteDifferenceImageFilter< TInputImage, TOutputImage >.

Reimplemented in itk::AntiAliasBinaryImageFilter< TInputImage, TOutputImage >, and itk::SegmentationLevelSetImageFilter< TInputImage, TOutputImage >.

Definition at line 242 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
typedef SmartPointer<Self> itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::Pointer
 

Reimplemented from itk::ImageToImageFilter< TInputImage, TOutputImage >.

Reimplemented in itk::AntiAliasBinaryImageFilter< TInputImage, TOutputImage >, itk::LaplacianSegmentationLevelSetImageFilter< TInputImage, TOutputImage >, itk::SegmentationLevelSetImageFilter< TInputImage, TOutputImage >, and itk::ThresholdSegmentationLevelSetImageFilter< TInputImage, TOutputImage >.

Definition at line 228 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
typedef SparseFieldLevelSetImageFilter itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::Self
 

Standard class typedefs

Reimplemented from itk::FiniteDifferenceImageFilter< TInputImage, TOutputImage >.

Reimplemented in itk::AntiAliasBinaryImageFilter< TInputImage, TOutputImage >, itk::LaplacianSegmentationLevelSetImageFilter< TInputImage, TOutputImage >, itk::SegmentationLevelSetImageFilter< TInputImage, TOutputImage >, and itk::ThresholdSegmentationLevelSetImageFilter< TInputImage, TOutputImage >.

Definition at line 226 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
typedef Image<StatusType, itkGetStaticConstMacro(ImageDimension) itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::StatusImageType)
 

The type of the image used to index status information. Necessary for the internals of the algorithm.

Definition at line 267 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
typedef char itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::StatusType
 

Type used for storing status information

Definition at line 262 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
typedef FiniteDifferenceImageFilter<TInputImage, TOutputImage> itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::Superclass
 

Reimplemented from itk::FiniteDifferenceImageFilter< TInputImage, TOutputImage >.

Reimplemented in itk::AntiAliasBinaryImageFilter< TInputImage, TOutputImage >, itk::LaplacianSegmentationLevelSetImageFilter< TInputImage, TOutputImage >, itk::SegmentationLevelSetImageFilter< TInputImage, TOutputImage >, and itk::ThresholdSegmentationLevelSetImageFilter< TInputImage, TOutputImage >.

Definition at line 227 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
typedef Superclass::TimeStepType itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::TimeStepType
 

Typedefs from the superclass

Reimplemented from itk::FiniteDifferenceImageFilter< TInputImage, TOutputImage >.

Reimplemented in itk::AntiAliasBinaryImageFilter< TInputImage, TOutputImage >, and itk::SegmentationLevelSetImageFilter< TInputImage, TOutputImage >.

Definition at line 232 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
typedef std::vector<ValueType> itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::UpdateBufferType
 

Container type used to store updates to the active layer.

Definition at line 274 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
typedef OutputImageType::ValueType itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::ValueType
 

The data type used in numerical computations. Derived from the output image type.

Reimplemented in itk::AntiAliasBinaryImageFilter< TInputImage, TOutputImage >, itk::LaplacianSegmentationLevelSetImageFilter< TInputImage, TOutputImage >, itk::SegmentationLevelSetImageFilter< TInputImage, TOutputImage >, and itk::ThresholdSegmentationLevelSetImageFilter< TInputImage, TOutputImage >.

Definition at line 249 of file itkSparseFieldLevelSetImageFilter.h.

Constructor & Destructor Documentation

template<class TInputImage, class TOutputImage>
itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::SparseFieldLevelSetImageFilter (    )  [protected]
 

template<class TInputImage, class TOutputImage>
itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::~SparseFieldLevelSetImageFilter (    )  [protected]
 

Member Function Documentation

template<class TInputImage, class TOutputImage>
void itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::AllocateUpdateBuffer (    )  [protected, virtual]
 

Reserves memory in the update buffer. Called before each iteration.

Implements itk::FiniteDifferenceImageFilter< TInputImage, TOutputImage >.

template<class TInputImage, class TOutputImage>
void itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::ApplyUpdate (  TimeStepType    dt )  [protected, virtual]
 

Applies the update buffer values to the active layer and reconstructs the sparse field layers for the next iteration.

Implements itk::FiniteDifferenceImageFilter< TInputImage, TOutputImage >.

template<class TInputImage, class TOutputImage>
TimeStepType itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::CalculateChange (    )  [protected, virtual]
 

Traverses the active layer list and calculates the change at these indicies to be applied in the current iteration.

Implements itk::FiniteDifferenceImageFilter< TInputImage, TOutputImage >.

template<class TInputImage, class TOutputImage>
virtual ValueType itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::CalculateUpdateValue (  const IndexType &    idx,
const TimeStepType &    dt,
const ValueType &    value,
const ValueType &    change
)  [inline, protected, virtual]
 

This function allows a subclass to override the way in which updates to output values are applied during each iteration. The default simply follows the standard finite difference scheme of scaling the change by the timestep and adding to the value of the previous iteration.

Reimplemented in itk::AntiAliasBinaryImageFilter< TInputImage, TOutputImage >.

Definition at line 302 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
void itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::ConstructActiveLayer (    )  [protected]
 

Constructs the active layer and initialize the first layers inside and outside of the active layer. The active layer defines the position of the zero level set by its values, which are constrained within a range around zero.

template<class TInputImage, class TOutputImage>
void itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::ConstructLayer (  StatusType    from,
StatusType    to
)  [protected]
 

Initializes a layer of the sparse field using a previously initialized layer. Builds the list of nodes in m_Layer[to] using m_Layer[from]. Marks values in the m_StatusImage.

template<class TInputImage, class TOutputImage>
void itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::CopyInputToOutput (    )  [protected, virtual]
 

Copies the input to the output image. Processing occurs on the output image, so the data type of the output image determines the precision of the calculations (i.e. double or float). This method overrides the parent class method to do some additional processing.

Reimplemented from itk::FiniteDifferenceImageFilter< TInputImage, TOutputImage >.

template<class TInputImage, class TOutputImage>
virtual const char* itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::GetClassName (    )  const [virtual]
 

Run-time type information (and related methods).

Reimplemented from itk::FiniteDifferenceImageFilter< TInputImage, TOutputImage >.

Reimplemented in itk::AntiAliasBinaryImageFilter< TInputImage, TOutputImage >, itk::LaplacianSegmentationLevelSetImageFilter< TInputImage, TOutputImage >, itk::SegmentationLevelSetImageFilter< TInputImage, TOutputImage >, and itk::ThresholdSegmentationLevelSetImageFilter< TInputImage, TOutputImage >.

template<class TInputImage, class TOutputImage>
virtual ValueType itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::GetIsoSurfaceValue (    )  [virtual]
 

Set/Get the value of the isosurface to use in the input image.

template<class TInputImage, class TOutputImage>
virtual unsigned int itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::GetNumberOfLayers (    )  [virtual]
 

Set/Get the number of layers to use in the sparse field. Argument is the number of layers on ONE side of the active layer, so the total layers in the sparse field is 2 * NumberOfLayers +1

template<class TInputImage, class TOutputImage>
virtual ValueType itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::GetRMSChange (    )  [virtual]
 

Get the RMS change calculated in the PREVIOUS iteration. This value is the square root of the average square of the change value of all pixels updated during the previous iteration.

template<class TInputImage, class TOutputImage>
void itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::Initialize (    )  [protected, virtual]
 

Constructs the sparse field layers and initializes their values.

Reimplemented from itk::FiniteDifferenceImageFilter< TInputImage, TOutputImage >.

template<class TInputImage, class TOutputImage>
void itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::InitializeActiveLayerValues (    )  [protected]
 

Initializes the values of the active layer set.

template<class TInputImage, class TOutputImage>
virtual void itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::InitializeBackgroundPixels (    )  [protected, virtual]
 

This method pre-processes pixels inside and outside the sparse field layers. The default is to set them to positive and negative values, respectively. This is not necessary as part of the calculations, but produces a more intuitive output for the user.

template<class TInputImage, class TOutputImage>
itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::itkStaticConstMacro (  ImageDimension   ,
unsigned    int,
TOutputImage::ImageDimension   
) 
 

template<class TInputImage, class TOutputImage>
Pointer itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::New (    )  [static]
 

Method for creation through the object factory.

Reimplemented from itk::ImageToImageFilter< TInputImage, TOutputImage >.

Reimplemented in itk::AntiAliasBinaryImageFilter< TInputImage, TOutputImage >, itk::LaplacianSegmentationLevelSetImageFilter< TInputImage, TOutputImage >, and itk::ThresholdSegmentationLevelSetImageFilter< TInputImage, TOutputImage >.

template<class TInputImage, class TOutputImage>
virtual void itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::PostProcessOutput (    )  [protected, virtual]
 

This method packages the output(s) into a consistent format. The default implementation produces a volume with the final solution values in the sparse field, and inside and outside values elsewhere as appropriate.

Reimplemented from itk::FiniteDifferenceImageFilter< TInputImage, TOutputImage >.

template<class TInputImage, class TOutputImage>
virtual void itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::PrintSelf (  std::ostream &    os,
Indent    indent
)  const [protected, virtual]
 

Methods invoked by Print() to print information about the object including superclasses. Typically not called by the user (use Print() instead) but used in the hierarchical print process to combine the output of several classes.

Reimplemented from itk::FiniteDifferenceImageFilter< TInputImage, TOutputImage >.

Reimplemented in itk::AntiAliasBinaryImageFilter< TInputImage, TOutputImage >, itk::LaplacianSegmentationLevelSetImageFilter< TInputImage, TOutputImage >, itk::SegmentationLevelSetImageFilter< TInputImage, TOutputImage >, and itk::ThresholdSegmentationLevelSetImageFilter< TInputImage, TOutputImage >.

template<class TInputImage, class TOutputImage>
void itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::ProcessOutsideList (  LayerType *    OutsideList,
StatusType    ChangeToStatus
)  [protected]
 

template<class TInputImage, class TOutputImage>
void itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::ProcessStatusList (  LayerType *    InputList,
LayerType *    OutputList,
StatusType    ChangeToStatus,
StatusType    SearchForStatus
)  [protected]
 

template<class TInputImage, class TOutputImage>
void itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::PropagateAllLayerValues (    )  [protected]
 

Adjusts the values associated with all the index layers of the sparse field by propagating out one layer at a time from the active set. This method also takes care of deleting nodes from the layers which have been marked in the status image as having been moved to other layers.

template<class TInputImage, class TOutputImage>
void itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::PropagateLayerValues (  StatusType    from,
StatusType    to,
StatusType    promote,
int    InOrOut
)  [protected]
 

Adjusts the values in a single layer "to" using values in a neighboring layer "from". The list of indicies in "to" are traversed and assigned new values appropriately. Any indicies in "to" without neighbors in "from" are moved into the "promote" layer (or deleted if "promote" is greater than the number of layers). "InOrOut" == 1 indicates this propagation is inwards (more negative). "InOrOut" == 2 indicates this propagation is outwards (more positive).

template<class TInputImage, class TOutputImage>
virtual void itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::SetIsoSurfaceValue (  ValueType    _arg )  [virtual]
 

Set/Get the value of the isosurface to use in the input image.

template<class TInputImage, class TOutputImage>
virtual void itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::SetNumberOfLayers (  unsigned int    _arg )  [virtual]
 

Set/Get the number of layers to use in the sparse field. Argument is the number of layers on ONE side of the active layer, so the total layers in the sparse field is 2 * NumberOfLayers +1

template<class TInputImage, class TOutputImage>
void itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::UpdateActiveLayerValues (  TimeStepType    dt,
LayerType *    StatusUpList,
LayerType *    StatusDownList
)  [protected]
 

Updates the active layer values using m_UpdateBuffer. Also creates an "up" and "down" list for promotion/demotion of indicies leaving the active set.

Member Data Documentation

template<class TInputImage, class TOutputImage>
double itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::m_ConstantGradientValue [static, protected]
 

The constant gradient to maintain between isosurfaces in the spare-field of the level-set image. This value defaults to 1.0

Definition at line 388 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
ValueType itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::m_IsoSurfaceValue [protected]
 

The value in the input which represents the isosurface of interest.

Definition at line 435 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
LayerNodeStorageType::Pointer itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::m_LayerNodeStore [protected]
 

Storage for layer node objects.

Definition at line 432 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
LayerListType itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::m_Layers [protected]
 

An array which contains all of the layers needed in the sparse field. Layers are organized as follows: m_Layer[0] = active layer, m_Layer[i:odd] = inside layer (i+1)/2, m_Layer[i:even] = outside layer i/2

Definition at line 421 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
SparseFieldCityBlockNeighborList<SmartNeighborhoodIterator<OutputImageType> > itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::m_NeighborList [protected]
 

Connectivity information for examining neighbor pixels.

Definition at line 384 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
unsigned int itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::m_NumberOfLayers [protected]
 

The number of layers to use in the sparse field. Sparse field will consist of m_NumberOfLayers layers on both sides of a single active layer. This active layer is the interface of interest, i.e. the zero level set.

Definition at line 426 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
ValueType itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::m_RMSChange [protected]
 

The RMS change calculated from each update. Can be used by a subclass to determine halting criteria. Valid only for the previous iteration, not during the current iteration. Calculated in ApplyUpdate.

Definition at line 444 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
OutputImageType::Pointer itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::m_ShiftedImage [protected]
 

This image is a copy of the input with m_IsoSurfaceValue subtracted from each pixel. This way we only need to consider the zero level set in our calculations. Makes the implementation easier and more efficient.

Definition at line 415 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
StatusType itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::m_StatusActiveChangingDown [static, protected]
 

Special status value which indicates a pending change to a more negative sparse field.

Definition at line 406 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
StatusType itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::m_StatusActiveChangingUp [static, protected]
 

Special status value which indicates a pending change to a more positive sparse field.

Definition at line 402 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
StatusType itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::m_StatusChanging [static, protected]
 

Special status value which indicates pending change to another sparse field layer.

Definition at line 398 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
StatusImageType::Pointer itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::m_StatusImage [protected]
 

An image of status values used internally by the algorithm.

Definition at line 429 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
StatusType itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::m_StatusNull [static, protected]
 

Special status value used as a default for indicies which have no meaningful status.

Definition at line 410 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
UpdateBufferType itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::m_UpdateBuffer [protected]
 

The update buffer used to store change values computed in CalculateChange.

Definition at line 439 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
ValueType itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::m_ValueOne [static, protected]
 

Multiplicative identity of the ValueType.

Definition at line 391 of file itkSparseFieldLevelSetImageFilter.h.

template<class TInputImage, class TOutputImage>
ValueType itk::SparseFieldLevelSetImageFilter< TInputImage, TOutputImage >::m_ValueZero [static, protected]
 

Additive identity of the ValueType.

Definition at line 394 of file itkSparseFieldLevelSetImageFilter.h.

The documentation for this class was generated from the following file:
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