itk::MRASlabIdentifier< TInputImage > Class Template Reference

identifies slab in MR images comparing minimum intensity averages. More...

#include <itkMRASlabIdentifier.h>

Inheritance diagram for itk::MRASlabIdentifier:

[legend]Collaboration diagram for itk::MRASlabIdentifier< TInputImage >:

[legend]List of all members.

Public Types
typedef MRASlabIdentifier	Self
typedef Object	Superclass
typedef SmartPointer< Self >	Pointer
typedef SmartPointer< const Self >	ConstPointer
typedef TInputImage	ImageType
typedef TInputImage::Pointer	ImagePointer
typedef TInputImage::ConstPointer	ImageConstPointer
typedef TInputImage::PixelType	ImagePixelType
typedef TInputImage::IndexType	ImageIndexType
typedef TInputImage::SizeType	ImageSizeType
typedef TInputImage::RegionType	ImageRegionType
typedef std::vector< ImageRegionType >	SlabRegionVectorType
Public Methods
virtual const char *	GetClassName () const
	itkSetConstObjectMacro (Image, ImageType)
virtual void	SetNumberOfMinimumsPerSlice (int _arg)
virtual int	GetNumberOfMinimumsPerSlice ()
void	GenerateSlabRegions (void)
SlabRegionVectorType	GetSlabRegionVector (void)
virtual void	SetSlicingDirection (int _arg)
virtual int	GetSlicingDirection ()
Static Public Methods
Pointer	New ()
Protected Methods
	MRASlabIdentifier ()
virtual	~MRASlabIdentifier ()
void	PrintSelf (std::ostream &os, Indent indent) const

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Detailed Description

template<class TInputImage>
class itk::MRASlabIdentifier< TInputImage >

identifies slab in MR images comparing minimum intensity averages.

This class is templated over the type of image. In many cases, a 3D MR image is constructed by merging smaller 3D blocks (slabs) which were acquired with different settings such as magnetic settings and patient positions. Therefore, stripe like patterns with slabs can be present in the resulting image. Such artifacts are called "slab boundary" artifacts or "venetian blind" artifacts.

With the slab boundary artifacts in an image, even a same tissue class's intensity values might vary significantly along the borders of slabs. Such rough value changes are not appropriate for some image processing methods. For example, MRIBiasFieldCorrectionFilter assumes a smooth bias field. However, with the slab boundary artifacts, the bias field estimation scheme that MRIBiasFieldCorrectionFilter uses might not adopt well. So, the MRIBiasFieldCorrectionFilter creates regions for slabs using the MRASlabIdentifier and then apply its bias correction scheme to each slab.

For this identifier, a slice means 2D image data which is extracted from the input image along one of three axes (x, y, z). Users can specify the slicing axis using the SetSlicingDirection(int dimension) member. (0 - x, 1 - y, 2 - z).

The identification scheme used here is very simple. 1) Users should specify how many pixels per slice the identifier will sample. 2) For each slice, the identifier searches the specified number of pixels of which intensity values are greater than 0 and less than those of the other pixels in the slice 3) The identifier calculates the average for each slice and the overall average using the search results. 4) For each slice, it subtracts the overall average from the slice average. If the sign of the subtraction result changes, then it assumes that a slab ends and another slab begins.

Definition at line 65 of file itkMRASlabIdentifier.h.

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Member Typedef Documentation

template<class TInputImage> typedef SmartPointer<const Self> itk::MRASlabIdentifier< TInputImage >::ConstPointer

Reimplemented from itk::Object. Definition at line 72 of file itkMRASlabIdentifier.h.

template<class TInputImage> typedef TInputImage::ConstPointer itk::MRASlabIdentifier< TInputImage >::ImageConstPointer

Const Pointer type for the image. Definition at line 87 of file itkMRASlabIdentifier.h.

template<class TInputImage> typedef TInputImage::IndexType itk::MRASlabIdentifier< TInputImage >::ImageIndexType

Definition at line 91 of file itkMRASlabIdentifier.h.

template<class TInputImage> typedef TInputImage::PixelType itk::MRASlabIdentifier< TInputImage >::ImagePixelType

Type definition for the input image pixel type. Definition at line 90 of file itkMRASlabIdentifier.h.

template<class TInputImage> typedef TInputImage::Pointer itk::MRASlabIdentifier< TInputImage >::ImagePointer

Pointer type for the image. Definition at line 84 of file itkMRASlabIdentifier.h.

template<class TInputImage> typedef TInputImage::RegionType itk::MRASlabIdentifier< TInputImage >::ImageRegionType

Definition at line 93 of file itkMRASlabIdentifier.h.

template<class TInputImage> typedef TInputImage::SizeType itk::MRASlabIdentifier< TInputImage >::ImageSizeType

Definition at line 92 of file itkMRASlabIdentifier.h.

template<class TInputImage> typedef TInputImage itk::MRASlabIdentifier< TInputImage >::ImageType

Type definition for the input image. Definition at line 81 of file itkMRASlabIdentifier.h.

template<class TInputImage> typedef SmartPointer<Self> itk::MRASlabIdentifier< TInputImage >::Pointer

Reimplemented from itk::Object. Definition at line 71 of file itkMRASlabIdentifier.h.

template<class TInputImage> typedef MRASlabIdentifier itk::MRASlabIdentifier< TInputImage >::Self

Standard class typedefs. Reimplemented from itk::Object. Definition at line 69 of file itkMRASlabIdentifier.h.

template<class TInputImage> typedef std::vector<ImageRegionType> itk::MRASlabIdentifier< TInputImage >::SlabRegionVectorType

Definition at line 94 of file itkMRASlabIdentifier.h.

template<class TInputImage> typedef Object itk::MRASlabIdentifier< TInputImage >::Superclass

Reimplemented from itk::Object. Definition at line 70 of file itkMRASlabIdentifier.h.

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Constructor & Destructor Documentation

template<class TInputImage> itk::MRASlabIdentifier< TInputImage >::MRASlabIdentifier (    )  [protected]

template<class TInputImage> virtual itk::MRASlabIdentifier< TInputImage >::~MRASlabIdentifier (    )  [inline, protected, virtual]

Definition at line 120 of file itkMRASlabIdentifier.h. References HardConnectedComponentImageFilter::PrintSelf().

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Member Function Documentation

template<class TInputImage> void itk::MRASlabIdentifier< TInputImage >::GenerateSlabRegions (  void    )

Compute the average values of miminum intensity pixels for each slice and compare the average values with overall averages.

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

Run-time type information (and related methods). Reimplemented from itk::Object.

template<class TInputImage> virtual int itk::MRASlabIdentifier< TInputImage >::GetNumberOfMinimumsPerSlice (    )  [virtual]

Get the number of minimum intensity pixels per slice.

template<class TInputImage> SlabRegionVectorType itk::MRASlabIdentifier< TInputImage >::GetSlabRegionVector (  void    )

Get slab regions.

template<class TInputImage> virtual int itk::MRASlabIdentifier< TInputImage >::GetSlicingDirection (    )  [virtual]

Set/Get the direction of slicing/ 0 - x axis, 1 - y axis, 2 - z axis

template<class TInputImage> itk::MRASlabIdentifier< TInputImage >::itkSetConstObjectMacro (  Image   , ImageType    )

Set the input image.

template<class TInputImage> Pointer itk::MRASlabIdentifier< TInputImage >::New (    )  [static]

Method for creation through the object factory. Reimplemented from itk::Object.

template<class TInputImage> void itk::MRASlabIdentifier< TInputImage >::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::Object.

template<class TInputImage> virtual void itk::MRASlabIdentifier< TInputImage >::SetNumberOfMinimumsPerSlice (  int    _arg )  [virtual]

Set the number of minimum intensity pixels per slice.

template<class TInputImage> virtual void itk::MRASlabIdentifier< TInputImage >::SetSlicingDirection (  int    _arg )  [virtual]

Set/Get the direction of slicing/ 0 - x axis, 1 - y axis, 2 - z axis

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

• itkMRASlabIdentifier.h

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