This filter implements a zero-crossing based edge detecor. More...

#include <itkZeroCrossingBasedEdgeDetectionImageFilter.h>

Inheritance diagram for itk::ZeroCrossingBasedEdgeDetectionImageFilter< TInputImage, TOutputImage >:

Collaboration diagram for itk::ZeroCrossingBasedEdgeDetectionImageFilter< TInputImage, TOutputImage >:

Public Types
typedef FixedArray< double, itkGetStaticConstMacro(ImageDimension) >	ArrayType
typedef SmartPointer< const Self >	ConstPointer
typedef TInputImage::PixelType	InputImagePixelType
typedef TInputImage	InputImageType
typedef TOutputImage::PixelType	OutputImagePixelType
typedef TOutputImage::RegionType	OutputImageRegionType
typedef TOutputImage	OutputImageType
typedef SmartPointer< Self >	Pointer
typedef ZeroCrossingBasedEdgeDetectionImageFilter	Self
typedef ImageToImageFilter < TInputImage, TOutputImage >	Superclass
Public Member Functions
virtual ::itk::LightObject::Pointer	CreateAnother (void) const
virtual const char *	GetNameOfClass () const
void	SetMaximumError (const typename ArrayType::ValueType v)
void	SetVariance (const typename ArrayType::ValueType v)
	typedef (Concept::SameDimension< ImageDimension, OutputImageDimension >) SameDimensionCheck
	typedef (Concept::EqualityComparable< OutputImagePixelType >) OutputEqualityComparableCheck
	typedef (Concept::IsFloatingPoint< InputImagePixelType >) PixelTypeIsFloatingPointCheck
	typedef (Concept::SameType< InputImagePixelType, OutputImagePixelType >) SameTypeCheck
	typedef (Concept::OStreamWritable< OutputImagePixelType >) OutputOStreamWritableCheck

virtual void	SetVariance (ArrayType _arg)
virtual const ArrayType	GetVariance () const
virtual void	SetMaximumError (ArrayType _arg)
virtual const ArrayType	GetMaximumError () const

virtual OutputImagePixelType	GetBackgroundValue () const
virtual void	SetBackgroundValue (OutputImagePixelType _arg)
virtual OutputImagePixelType	GetForegroundValue () const
virtual void	SetForegroundValue (OutputImagePixelType _arg)
Static Public Member Functions
static Pointer	New ()
Static Public Attributes

static const unsigned int	ImageDimension = TInputImage::ImageDimension
static const unsigned int	OutputImageDimension = TOutputImage::ImageDimension
Protected Member Functions
void	GenerateData ()
void	PrintSelf (std::ostream &os, Indent indent) const
	~ZeroCrossingBasedEdgeDetectionImageFilter ()

	ZeroCrossingBasedEdgeDetectionImageFilter ()
Private Member Functions
void	operator= (const Self &)
	ZeroCrossingBasedEdgeDetectionImageFilter (const Self &)
Private Attributes
OutputImagePixelType	m_BackgroundValue
OutputImagePixelType	m_ForegroundValue
ArrayType	m_MaximumError
ArrayType	m_Variance

Detailed Description

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

This filter implements a zero-crossing based edge detecor.

The zero-crossing based edge detector looks for pixels in the Laplacian of an image where the value of the Laplacian passes through zero --- points where the Laplacian changes sign. Such points often occur at ``edges'' in images --- i.e. points where the intensity of the image changes rapidly, but they also occur at places that are not as easy to associate with edges. It is best to think of the zero crossing detector as some sort of feature detector rather than as a specific edge detector.

: Zero crossings always lie on closed contours and so the output from the zero crossing detector is usually a binary image with single pixel thickness lines showing the positions of the zero crossing points.

: In this implementation, the input image is first smoothed with a Gaussian filter, then the LaplacianImageFilter is applied to smoothed image. Finally the zero-crossing of the Laplacian of the smoothed image is detected. The output is a binary image.

Inputs and Outputs: The input to the filter should be a scalar, itk::Image of arbitrary dimension. The output image is a binary, labeled image. See itkZeroCrossingImageFilter for more information on requirements of the data type of the output.

: To use this filter, first set the parameters (variance and maximum error) needed by the embedded DiscreteGaussianImageFilter, i.e. See DiscreteGaussianImageFilter for information about these parameters. Optionally, you may also set foreground and background values for the zero-crossing filter. The default label values are Zero for the background and One for the foreground, as defined in NumericTraits for the data type of the output image.

See also:: DiscreteGaussianImageFilter; LaplacianImageFilter; ZeroCrossingImageFilter

Definition at line 70 of file itkZeroCrossingBasedEdgeDetectionImageFilter.h.