ITK
6.0.0
Insight Toolkit
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#include <itkGeodesicActiveContourShapePriorLevelSetFunction.h>
This function is used in GeodesicActiveContourShapePriorSegmentationLevelSetFilter to segment structures in an image based on user supplied edge potential map and shape model.
GeodesicActiveContourShapePriorLevelSetFunction is a subclass of the generic LevelSetFunction. It is used to segment structures in an image based on a user supplied edge potential map \( g(I) \), which has values close to zero in regions near edges (or high image gradient) and values close to one in regions with relatively constant intensity. Typically, the edge potential map is a function of the gradient, for example:
\[ g(I) = 1 / ( 1 + | (\nabla * G)(I)| ) \]
\[ g(I) = \exp^{-|(\nabla * G)(I)|} \]
where \( I \) is image intensity and \( (\nabla * G) \) is the derivative of Gaussian operator.
The edge potential image is set via the SetFeatureImage() method.
In this function both the propagation term \( P(\mathbf{x}) \) and the curvature spatial modifier term \( Z(\mathbf{x}) \) are taken directly from the edge potential image such that:
\[ P(\mathbf{x}) = g(\mathbf{x}) \]
\[ Z(\mathbf{x}) = g(\mathbf{x}) \]
An advection term \( \mathbf{A}(\mathbf{x}) \) is constructed from the negative gradient of the edge potential image.
\[ \mathbf{A}(\mathbf{x}) = -\nabla g(\mathbf{x}) \]
This term behaves like a doublet attracting the contour to the edges.
This class extends the basic LevelSetFunction with a shape prior term as developed in [1].
\( \zeta( \phi^{*} - \phi) \)
where \( \phi^{*} \) is the signed distance function from a target shape and \( \zeta \) is a scalar constant.
The target shape signed distance function is supplied through a ShapeSignedDistanceFunction object. Typically, the shape is a function of a set of parameters.
Definition at line 93 of file itkGeodesicActiveContourShapePriorLevelSetFunction.h.
Static Public Member Functions | |
static Pointer | New () |
Static Public Member Functions inherited from itk::ShapePriorSegmentationLevelSetFunction< TImageType, TImageType > | |
static Pointer | New () |
Static Public Member Functions inherited from itk::LevelSetFunction< TImageType > | |
static double | GetMaximumCurvatureTimeStep () |
static double | GetMaximumPropagationTimeStep () |
static Pointer | New () |
static void | SetMaximumCurvatureTimeStep (double n) |
static void | SetMaximumPropagationTimeStep (double n) |
Static Public Member Functions inherited from itk::LightObject | |
static void | BreakOnError () |
static Pointer | New () |
Static Public Attributes | |
static constexpr unsigned int | ImageDimension = Superclass::ImageDimension |
Static Public Attributes inherited from itk::ShapePriorSegmentationLevelSetFunction< TImageType, TImageType > | |
static constexpr unsigned int | ImageDimension |
Static Public Attributes inherited from itk::SegmentationLevelSetFunction< TImageType, TImageType > | |
static constexpr unsigned int | ImageDimension |
Static Public Attributes inherited from itk::LevelSetFunction< TImageType > | |
static constexpr unsigned int | ImageDimension = Superclass::ImageDimension |
Static Public Attributes inherited from itk::FiniteDifferenceFunction< TImageType > | |
static constexpr unsigned int | ImageDimension = ImageType::ImageDimension |
Private Attributes | |
double | m_DerivativeSigma {} |
using itk::GeodesicActiveContourShapePriorLevelSetFunction< TImageType, TFeatureImageType >::ConstPointer = SmartPointer<const Self> |
Definition at line 103 of file itkGeodesicActiveContourShapePriorLevelSetFunction.h.
using itk::GeodesicActiveContourShapePriorLevelSetFunction< TImageType, TFeatureImageType >::FeatureImageType = TFeatureImageType |
Definition at line 104 of file itkGeodesicActiveContourShapePriorLevelSetFunction.h.
using itk::GeodesicActiveContourShapePriorLevelSetFunction< TImageType, TFeatureImageType >::Pointer = SmartPointer<Self> |
Definition at line 102 of file itkGeodesicActiveContourShapePriorLevelSetFunction.h.
using itk::GeodesicActiveContourShapePriorLevelSetFunction< TImageType, TFeatureImageType >::Self = GeodesicActiveContourShapePriorLevelSetFunction |
Standard class type aliases.
Definition at line 100 of file itkGeodesicActiveContourShapePriorLevelSetFunction.h.
using itk::GeodesicActiveContourShapePriorLevelSetFunction< TImageType, TFeatureImageType >::Superclass = ShapePriorSegmentationLevelSetFunction<TImageType, TFeatureImageType> |
Definition at line 101 of file itkGeodesicActiveContourShapePriorLevelSetFunction.h.
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inlineprotected |
Definition at line 168 of file itkGeodesicActiveContourShapePriorLevelSetFunction.h.
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overrideprotecteddefault |
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overridevirtual |
Compute the advection field from feature image.
Reimplemented from itk::SegmentationLevelSetFunction< TImageType, TImageType >.
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overridevirtual |
Compute speed image from feature image.
Reimplemented from itk::SegmentationLevelSetFunction< TImageType, TImageType >.
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inlineoverridevirtual |
The curvature speed is same as the propagation speed.
Reimplemented from itk::LevelSetFunction< TImageType >.
Definition at line 135 of file itkGeodesicActiveContourShapePriorLevelSetFunction.h.
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inline |
Set/Get the sigma for the Gaussian kernel used to compute the gradient of the feature image needed for the advection term of the equation.
Definition at line 150 of file itkGeodesicActiveContourShapePriorLevelSetFunction.h.
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overridevirtual |
Reimplemented from itk::FiniteDifferenceFunction< TImageType >.
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inlineoverridevirtual |
This method creates the appropriate member variable operators for the level-set calculations. The argument to this function is a the radius necessary for performing the level-set calculations.
Reimplemented from itk::LevelSetFunction< TImageType >.
Definition at line 157 of file itkGeodesicActiveContourShapePriorLevelSetFunction.h.
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static |
Method for creation through the object factory.
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overrideprotectedvirtual |
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::FiniteDifferenceFunction< TImageType >.
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inline |
Set/Get the sigma for the Gaussian kernel used to compute the gradient of the feature image needed for the advection term of the equation.
Definition at line 145 of file itkGeodesicActiveContourShapePriorLevelSetFunction.h.
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staticconstexpr |
Extract some parameters from the superclass.
Definition at line 123 of file itkGeodesicActiveContourShapePriorLevelSetFunction.h.
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private |
Definition at line 184 of file itkGeodesicActiveContourShapePriorLevelSetFunction.h.