lti::watershedSegmentation Class Reference

Watershed segmentation of a channel8. More...

#include <ltiWatershedSegmentation.h>

Inheritance diagram for lti::watershedSegmentation:

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Collaboration diagram for lti::watershedSegmentation:

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List of all members.

Classes
class	parameters
	the parameters for the class watershedSegmentation More...
Public Member Functions
	watershedSegmentation ()
	watershedSegmentation (const parameters &par)
	watershedSegmentation (const watershedSegmentation &other)
virtual	~watershedSegmentation ()
virtual const char *	getTypeName () const
bool	apply (channel8 &srcdest)
bool	apply (const channel8 &src, channel8 &dest)
bool	apply (const channel8 &src, matrix< int > &result)
watershedSegmentation &	copy (const watershedSegmentation &other)
virtual functor *	clone () const
const parameters &	getParameters () const

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Detailed Description

Watershed segmentation of a channel8.

Algorithms:

Luc Vincent and Pierre Soille. "Watersheds in Digital Spaces: An Efficient Algorithm Based on Immersion Simulations". IEEE transactions on pattern analysis and machine intelligence, vol. 13, No. 6, June 1991, pp. 583-598

and

Patrick De Smet and Rui Luis V.P.M. Pires "Implementation and analysis of an optimized rainfalling watershed algorithm". IS&T\/SPIE's 12th Annual Symposium Electronic Imaging 2000, January 2000, pp. 759-766

Watershed segmentation is a morphological operator used to segment gray valued images, based on viewing the gray image as a topographical map. Valleys will be flooded with water until the water surpasses the sheds separating them. At the contact lines the "watershed lines" are created and constitute the limits between the image regions.

The topological map is usually a gradient map (the magnitude of the gradient) that can be obtained with the lti::orientationMap functor or with the lti::colorContrastGradient, or directly using the lti::gradientKernelX and lti::gradientKernelY and the lti::convolution operator.

Two kinds of apply() methods are provided:

• Two methods returning a channel8 will compute only two values: watershed or the catchment basin. The specific values for each class are indicated in the parameters object.

• The apply() method returning a matrix<int> return a labeled mask, where each catchment basin get its own id. This method is more typical for a segmentation algorithm.

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Constructor & Destructor Documentation

lti::watershedSegmentation::watershedSegmentation

(

)

default constructor

lti::watershedSegmentation::watershedSegmentation

(

const parameters &

par

)

constructor with parameters

lti::watershedSegmentation::watershedSegmentation

(

const watershedSegmentation &

other

)

copy constructor

Parameters:

other

the object to be copied

virtual lti::watershedSegmentation::~watershedSegmentation

(

)

[virtual]

destructor

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Member Function Documentation

bool lti::watershedSegmentation::apply	(	const channel8 &	src,
		matrix< int > &	result
	)

creates a region mask on the given matrix only exact watersheds are marked 0, regions are numbered 1,2,.

..

Parameters:

	src	channel8 with the source data. This is usually the gradient of an intensity image or a color contrast gradient.
	result	matrix<int> with the resulting region information, with a label per basin.

bool lti::watershedSegmentation::apply	(	const channel8 &	src,
		channel8 &	dest
	)

saves a watershed mask of src in dest

Parameters:

	src	channel8 with the source data. This is usually the gradient of an intensity image or a color contrast gradient.
	dest	channel8 where the watershed lines will be written.

bool lti::watershedSegmentation::apply

(

channel8 &

srcdest

)

creates a watershed mask on the given channel8

Parameters:

srcdest

channel8 with the source data. This is usually the gradient of an intensity image or a color contrast gradient. The resulting watershed lines will be left here too.

Returns:

true if successful, false otherwise

virtual functor* lti::watershedSegmentation::clone

(

)

const [virtual]

returns a pointer to a clone of this functor.

Reimplemented from lti::segmentation.

watershedSegmentation& lti::watershedSegmentation::copy

(

const watershedSegmentation &

other

)

copy data of "other" functor.

Parameters:

other

the functor to be copied

Returns:

a reference to this functor object

Reimplemented from lti::segmentation.

const parameters& lti::watershedSegmentation::getParameters

(

)

const

returns used parameters

Reimplemented from lti::functor.

virtual const char* lti::watershedSegmentation::getTypeName

(

)

const [virtual]

returns the name of this type ("watershedSegmentation")

Reimplemented from lti::segmentation.

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

• ltiWatershedSegmentation.h