ITK
4.6.0
Insight Segmentation and Registration Toolkit
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#include <itkCurvatureFlowImageFilter.h>
Denoise an image using curvature driven flow.
CurvatureFlowImageFilter implements a curvature driven image denoising algorithm. Iso-brightness contours in the grayscale input image are viewed as a level set. The level set is then evolved using a curvature-based speed function:
where is the curvature.
The advantage of this approach is that sharp boundaries are preserved with smoothing occurring only within a region. However, it should be noted that continuous application of this scheme will result in the eventual removal of all information as each contour shrinks to zero and disappear.
Note that unlike level set segmentation algorithms, the image to be denoised is already the level set and can be set directly as the input using the SetInput() method.
This filter has two parameters: the number of update iterations to be performed and the timestep between each update.
The timestep should be "small enough" to ensure numerical stability. Stability is guarantee when the timestep meets the CFL (Courant-Friedrichs-Levy) condition. Broadly speaking, this condition ensures that each contour does not move more than one grid position at each timestep. In the literature, the timestep is typically user specified and have to manually tuned to the application.
This filter make use of the multi-threaded finite difference solver hierarchy. Updates are computed using a CurvatureFlowFunction object. A zero flux Neumann boundary condition when computing derivatives near the data boundary.
This filter may be streamed. To support streaming this filter produces a padded output which takes into account edge effects. The size of the padding is m_NumberOfIterations on each edge. Users of this filter should only make use of the center valid central region.
Reference: "Level Set Methods and Fast Marching Methods", J.A. Sethian, Cambridge Press, Chapter 16, Second edition, 1999.
Input/Output Restrictions: TInputImage and TOutputImage must have the same dimension. TOutputImage's pixel type must be a real number type.
Definition at line 90 of file itkCurvatureFlowImageFilter.h.
Static Public Member Functions | |
static Pointer | New () |
Static Public Member Functions inherited from itk::Object | |
static bool | GetGlobalWarningDisplay () |
static void | GlobalWarningDisplayOff () |
static void | GlobalWarningDisplayOn () |
static Pointer | New () |
static void | SetGlobalWarningDisplay (bool flag) |
Static Public Member Functions inherited from itk::LightObject | |
static void | BreakOnError () |
static Pointer | New () |
Static Public Attributes | |
static const unsigned int | ImageDimension = Superclass::ImageDimension |
Static Public Attributes inherited from itk::DenseFiniteDifferenceImageFilter< TInputImage, TOutputImage > | |
static const unsigned int | ImageDimension = Superclass::ImageDimension |
Static Public Attributes inherited from itk::FiniteDifferenceImageFilter< TInputImage, TOutputImage > | |
static const unsigned int | ImageDimension = OutputImageType::ImageDimension |
Static Public Attributes inherited from itk::InPlaceImageFilter< TInputImage, TOutputImage > | |
static const unsigned int | InputImageDimension = TInputImage::ImageDimension |
static const unsigned int | OutputImageDimension = TOutputImage::ImageDimension |
Static Public Attributes inherited from itk::ImageToImageFilter< TInputImage, TOutputImage > | |
static const unsigned int | InputImageDimension = TInputImage::ImageDimension |
static const unsigned int | OutputImageDimension = TOutputImage::ImageDimension |
Static Public Attributes inherited from itk::ImageSource< TOutputImage > | |
static const unsigned int | OutputImageDimension = TOutputImage::ImageDimension |
Private Member Functions | |
CurvatureFlowImageFilter (const Self &) | |
void | operator= (const Self &) |
Private Attributes | |
TimeStepType | m_TimeStep |
typedef SmartPointer< const Self > itk::CurvatureFlowImageFilter< TInputImage, TOutputImage >::ConstPointer |
Definition at line 98 of file itkCurvatureFlowImageFilter.h.
typedef CurvatureFlowFunction< OutputImageType > itk::CurvatureFlowImageFilter< TInputImage, TOutputImage >::CurvatureFlowFunctionType |
CurvatureFlowFunction type.
Definition at line 120 of file itkCurvatureFlowImageFilter.h.
typedef Superclass::FiniteDifferenceFunctionType itk::CurvatureFlowImageFilter< TInputImage, TOutputImage >::FiniteDifferenceFunctionType |
FiniteDifferenceFunction type.
Definition at line 116 of file itkCurvatureFlowImageFilter.h.
typedef Superclass::InputImageType itk::CurvatureFlowImageFilter< TInputImage, TOutputImage >::InputImageType |
InputImage type.
Definition at line 105 of file itkCurvatureFlowImageFilter.h.
typedef OutputImageType::Pointer itk::CurvatureFlowImageFilter< TInputImage, TOutputImage >::OutputImagePointer |
Definition at line 112 of file itkCurvatureFlowImageFilter.h.
typedef Superclass::OutputImageType itk::CurvatureFlowImageFilter< TInputImage, TOutputImage >::OutputImageType |
OutputImage type.
Definition at line 111 of file itkCurvatureFlowImageFilter.h.
typedef Superclass::PixelType itk::CurvatureFlowImageFilter< TInputImage, TOutputImage >::PixelType |
The pixel type of the output image will be used in computations. Inherited from the superclass.
Definition at line 128 of file itkCurvatureFlowImageFilter.h.
typedef SmartPointer< Self > itk::CurvatureFlowImageFilter< TInputImage, TOutputImage >::Pointer |
Definition at line 97 of file itkCurvatureFlowImageFilter.h.
typedef CurvatureFlowImageFilter itk::CurvatureFlowImageFilter< TInputImage, TOutputImage >::Self |
Standard class typedefs.
Definition at line 95 of file itkCurvatureFlowImageFilter.h.
typedef DenseFiniteDifferenceImageFilter< TInputImage, TOutputImage > itk::CurvatureFlowImageFilter< TInputImage, TOutputImage >::Superclass |
Definition at line 96 of file itkCurvatureFlowImageFilter.h.
typedef Superclass::TimeStepType itk::CurvatureFlowImageFilter< TInputImage, TOutputImage >::TimeStepType |
The time step type. Inherited from the superclass.
Definition at line 131 of file itkCurvatureFlowImageFilter.h.
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Definition at line 160 of file itkCurvatureFlowImageFilter.h.
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Create an object from an instance, potentially deferring to a factory. This method allows you to create an instance of an object that is exactly the same type as the referring object. This is useful in cases where an object has been cast back to a base class.
Reimplemented from itk::Object.
Reimplemented in itk::MinMaxCurvatureFlowImageFilter< TInputImage, TOutputImage >.
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To support streaming, this filter produces a output which is larger than the original requested region. The output is padding by m_NumberOfIterations pixels on edge.
Reimplemented from itk::ProcessObject.
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Edge effects are taken care of by padding the output requested region. As such, the input requested region needs to at minimum the same size as the output requested region.
Reimplemented from itk::FiniteDifferenceImageFilter< TInputImage, TOutputImage >.
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Run-time type information (and related methods).
Reimplemented from itk::DenseFiniteDifferenceImageFilter< TInputImage, TOutputImage >.
Reimplemented in itk::MinMaxCurvatureFlowImageFilter< TInputImage, TOutputImage >, and itk::BinaryMinMaxCurvatureFlowImageFilter< TInputImage, TOutputImage >.
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Get the timestep parameter.
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Supplies the halting criteria for this class of filters. The algorithm will stop after a user-specified number of iterations.
Reimplemented from itk::FiniteDifferenceImageFilter< TInputImage, TOutputImage >.
Definition at line 165 of file itkCurvatureFlowImageFilter.h.
References itk::FiniteDifferenceImageFilter< TInputImage, TOutputImage >::GetElapsedIterations(), and itk::FiniteDifferenceImageFilter< TInputImage, TOutputImage >::GetNumberOfIterations().
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Initialize the state of filter and equation before each iteration. Progress feeback is implemented as part of this method.
Reimplemented from itk::FiniteDifferenceImageFilter< TInputImage, TOutputImage >.
Reimplemented in itk::MinMaxCurvatureFlowImageFilter< TInputImage, TOutputImage >, and itk::BinaryMinMaxCurvatureFlowImageFilter< TInputImage, TOutputImage >.
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Method for creation through the object factory.
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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::DenseFiniteDifferenceImageFilter< TInputImage, TOutputImage >.
Reimplemented in itk::MinMaxCurvatureFlowImageFilter< TInputImage, TOutputImage >.
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Set the timestep parameter.
itk::CurvatureFlowImageFilter< TInputImage, TOutputImage >::typedef | ( | Concept::Convertible< double, PixelType > | ) |
This class requires DoubleConvertibleToOutputCheck in the form of ( Concept::Convertible< double, PixelType > )
itk::CurvatureFlowImageFilter< TInputImage, TOutputImage >::typedef | ( | Concept::Convertible< PixelType, double > | ) |
This class requires OutputConvertibleToDoubleCheck in the form of ( Concept::Convertible< PixelType, double > )
itk::CurvatureFlowImageFilter< TInputImage, TOutputImage >::typedef | ( | Concept::DivisionOperators< PixelType > | ) |
This class requires OutputDivisionOperatorsCheck in the form of ( Concept::DivisionOperators< PixelType > )
itk::CurvatureFlowImageFilter< TInputImage, TOutputImage >::typedef | ( | Concept::MultiplyOperator< double, PixelType, PixelType > | ) |
This class requires DoubleOutputMultiplyOperatorCheck in the form of ( Concept::MultiplyOperator< double, PixelType, PixelType > )
itk::CurvatureFlowImageFilter< TInputImage, TOutputImage >::typedef | ( | Concept::MultiplyOperator< int, PixelType, PixelType > | ) |
This class requires IntOutputMultiplyOperatorCheck in the form of ( Concept::MultiplyOperator< int, PixelType, PixelType > )
itk::CurvatureFlowImageFilter< TInputImage, TOutputImage >::typedef | ( | Concept::LessThanComparable< PixelType, double > | ) |
This class requires OutputLessThanDoubleCheck in the form of ( Concept::LessThanComparable< PixelType, double > )
itk::CurvatureFlowImageFilter< TInputImage, TOutputImage >::typedef | ( | Concept::AdditiveOperators< PixelType, double > | ) |
This class requires OutputDoubleAdditiveOperatorsCheck in the form of ( Concept::AdditiveOperators< PixelType, double > )
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Dimensionality of input and output data is assumed to be the same. It is inherited from the superclass.
Definition at line 124 of file itkCurvatureFlowImageFilter.h.
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Definition at line 196 of file itkCurvatureFlowImageFilter.h.