#include <itkMorphologicalWatershedFromMarkersImageFilter.h>

Inheritance diagram for itk::MorphologicalWatershedFromMarkersImageFilter< TInputImage, TLabelImage >:

Collaboration diagram for itk::MorphologicalWatershedFromMarkersImageFilter< TInputImage, TLabelImage >:

Public Types
typedef SmartPointer< const Self >	ConstPointer
typedef LabelImageType::IndexType	IndexType
typedef InputImageType::ConstPointer	InputImageConstPointer
typedef InputImageType::PixelType	InputImagePixelType
typedef InputImageType::Pointer	InputImagePointer
typedef InputImageType::RegionType	InputImageRegionType
typedef TInputImage	InputImageType
typedef LabelImageType::ConstPointer	LabelImageConstPointer
typedef LabelImageType::PixelType	LabelImagePixelType
typedef LabelImageType::Pointer	LabelImagePointer
typedef LabelImageType::RegionType	LabelImageRegionType
typedef TLabelImage	LabelImageType
typedef SmartPointer< Self >	Pointer
typedef MorphologicalWatershedFromMarkersImageFilter	Self
typedef ImageToImageFilter < TInputImage, TLabelImage >	Superclass
Public Member Functions
virtual ::itk::LightObject::Pointer	CreateAnother (void) const
const LabelImageType *	GetMarkerImage () const
virtual const char *	GetNameOfClass () const
void	SetInput1 (const TInputImage *input)
void	SetInput2 (const TLabelImage *input)
void	SetMarkerImage (const TLabelImage *input)

virtual void	SetFullyConnected (bool _arg)
virtual const bool &	GetFullyConnected ()
virtual void	FullyConnectedOn ()
virtual void	FullyConnectedOff ()
Static Public Member Functions
static Pointer	New ()
Static Public Attributes
static const unsigned int	ImageDimension = TInputImage::ImageDimension
Protected Member Functions
void	EnlargeOutputRequestedRegion (DataObject *)
void	GenerateData ()
void	GenerateInputRequestedRegion ()
Private Member Functions
	MorphologicalWatershedFromMarkersImageFilter (const Self &)
void	operator= (const Self &)
Private Attributes
bool	m_FullyConnected
bool	m_MarkWatershedLine
virtual void	SetMarkWatershedLine (bool _arg)
virtual const bool &	GetMarkWatershedLine ()
virtual void	MarkWatershedLineOn ()
virtual void	MarkWatershedLineOff ()
	MorphologicalWatershedFromMarkersImageFilter ()
	~MorphologicalWatershedFromMarkersImageFilter ()
void	PrintSelf (std::ostream &os, Indent indent) const

Detailed Description

template<class TInputImage, class TLabelImage>
class itk::MorphologicalWatershedFromMarkersImageFilter< TInputImage, TLabelImage >

Morphological watershed transform from markers.

The watershed transform is a tool for image segmentation that is fast and flexible and potentially fairly parameter free. It was originally derived from a geophysical model of rain falling on a terrain and a variety of more formal definitions have been devised to allow development of practical algorithms. If an image is considered as a terrain and divided into catchment basins then the hope is that each catchment basin would contain an object of interest.

The output is a label image. A label image, sometimes referred to as a categorical image, has unique values for each region. For example, if a watershed produces 2 regions, all pixels belonging to one region would have value A, and all belonging to the other might have value B. Unassigned pixels, such as watershed lines, might have the background value (0 by convention).

The simplest way of using the watershed is to preprocess the image we want to segment so that the boundaries of our objects are bright (e.g apply an edge detector) and compute the watershed transform of the edge image. Watershed lines will correspond to the boundaries and our problem will be solved. This is rarely useful in practice because there are always more regional minima than there are objects, either due to noise or natural variations in the object surfaces. Therefore, while many watershed lines do lie on significant boundaries, there are many that don't. Various methods can be used to reduce the number of minima in the image, like thresholding the smallest values, filtering the minima and/or smoothing the image.

This filter use another approach to avoid the problem of over segmentation: it let the user provide a marker image which mark the minima in the input image and give them a label. The minima are imposed in the input image by the markers. The labels of the output image are the label of the marker image.

The morphological watershed transform algorithm is described in Chapter 9.2 of Pierre Soille's book "Morphological Image Analysis: Principles and Applications", Second Edition, Springer, 2003.

This code was contributed in the Insight Journal paper: "The watershed transform in ITK - discussion and new developments" by Beare R., Lehmann G. http://hdl.handle.net/1926/202 http://www.insight-journal.org/browse/publication/92

Author:: Gaetan Lehmann. Biologie du Developpement et de la Reproduction, INRA de Jouy-en-Josas, France.; Richard Beare. Department of Medicine, Monash University, Melbourne, Australia.

See also:: WatershedImageFilter, MorphologicalWatershedImageFilter

Definition at line 80 of file itkMorphologicalWatershedFromMarkersImageFilter.h.