DGtal::GreedySegmentation< TSegmentComputer > Class Template Reference

Aim: Computes the greedy segmentation of a range given by a pair of ConstIterators. The last element of a given segment is the first one one of the next segment. More...

#include <DGtal/geometry/curves/GreedySegmentation.h>

Data Structures
class	SegmentComputerIterator
	Aim: Specific iterator to visit all the segments of a greedy segmentation. More...

Public Types
typedef TSegmentComputer	SegmentComputer
typedef SegmentComputer::ConstIterator	ConstIterator

Public Member Functions
	BOOST_CONCEPT_ASSERT ((concepts::CForwardSegmentComputer< TSegmentComputer >))
	GreedySegmentation ()
	GreedySegmentation (const ConstIterator &itb, const ConstIterator &ite, const SegmentComputer &aSegmentComputer)
void	setSubRange (const ConstIterator &itb, const ConstIterator &ite)
void	setMode (const std::string &aMode)
	~GreedySegmentation ()
GreedySegmentation::SegmentComputerIterator	begin () const
GreedySegmentation::SegmentComputerIterator	end () const
void	selfDisplay (std::ostream &out) const
bool	isValid () const

Private Member Functions
	GreedySegmentation (const GreedySegmentation &other)
GreedySegmentation &	operator= (const GreedySegmentation &other)

Private Attributes
ConstIterator	myBegin
ConstIterator	myEnd
ConstIterator	myStart
ConstIterator	myStop
std::string	myMode
SegmentComputer	mySegmentComputer

Detailed Description

template<typename TSegmentComputer>
class DGtal::GreedySegmentation< TSegmentComputer >

Aim: Computes the greedy segmentation of a range given by a pair of ConstIterators. The last element of a given segment is the first one one of the next segment.

Description of template class 'GreedySegmentation'

This class is a model of CSegmentation.

Template Parameters

TSegmentComputer

at least a model of concepts::CForwardSegmentComputer (an online algorithm for the recognition of a given class of segments).

In the short example below, a digital curve stored in a STL vector is decomposed into 8-connected DSSs whose parameters are sent to the standard output.

//types definition
typedef PointVector<2,int> Point;
typedef std::vector<Point> Range;
typedef Range::const_iterator ConstIterator;
typedef ArithmeticalDSSComputer<ConstIterator,int,8> SegmentComputer;
typedef GreedySegmentation<SegmentComputer> Segmentation;
 
//input points
Range curve;
curve.push_back(Point(1,1));
curve.push_back(Point(2,1));
curve.push_back(Point(3,2));
curve.push_back(Point(4,2));
curve.push_back(Point(5,2));
curve.push_back(Point(6,2));
curve.push_back(Point(7,2));
curve.push_back(Point(8,1));
curve.push_back(Point(9,1));
 
//Segmentation
SegmentComputer recognitionAlgorithm;
Segmentation theSegmentation(curve.begin(), curve.end(), recognitionAlgorithm);
       
Segmentation::SegmentComputerIterator i = theSegmentation.begin();
Segmentation::SegmentComputerIterator end = theSegmentation.end();
for ( ; i != end; ++i) {
  SegmentComputer current(*i);
  trace.info() << current << std::endl;  //standard output
} 

If you want to get the DSSs segmentation of the digital curve when it is scanned in the reverse way, you can use the reverse iterator of the STL vector:

typedef Range::const_reverse_iterator ConstReverseIterator;
 
Segmentation theSegmentation(curve.rbegin(), curve.rend(), recognitionAlgorithm);

If you want to get the DSSs segmentation of a part of the digital curve (not the whole digital curve), you can give the range to process as a pair of iterators when calling the setSubRange() method as follow:

theSegmentation.setSubRange(beginIt, endIt);

Obviously, [beginIt, endIt) has to be a valid range included in the wider range [curve.begin(), curve.end()).

Moreover, a part of a digital curve may be processed either as an independant (open) digital curve or as a part whose segmentation at the ends depends of the underlying digital curve. That's why 3 processing modes are available:

• "Truncate" (default), the extension of the last segment (and the segmentation) stops just before endIt.
• "Truncate+1", the last segment is extended to endIt too if it is possible, provided that endIt != curve.end().
• "DoNotTruncate", the last segment is extended as far as possible, provided that curve.end() is not reached.

In order to set a mode (before getting a SegmentComputerIterator), use the setMode() method as follow:

theSegmentation.setMode("DoNotTruncate");

Note that the default mode will be used for any unknown modes.

See also

testSegmentation.cpp

Examples

geometry/curves/exampleArithDSS3d.cpp, geometry/curves/exampleFrechetShortcut.cpp, geometry/curves/greedy-dss-decomposition.cpp, and geometry/curves/greedyAlphaThickDecomposition.cpp.

Definition at line 149 of file GreedySegmentation.h.

Member Typedef Documentation

ConstIterator

template<typename TSegmentComputer >

typedef SegmentComputer::ConstIterator DGtal::GreedySegmentation< TSegmentComputer >::ConstIterator

Definition at line 156 of file GreedySegmentation.h.

SegmentComputer

template<typename TSegmentComputer >

typedef TSegmentComputer DGtal::GreedySegmentation< TSegmentComputer >::SegmentComputer

Definition at line 155 of file GreedySegmentation.h.

Constructor & Destructor Documentation

GreedySegmentation() [1/3]

template<typename TSegmentComputer >

DGtal::GreedySegmentation< TSegmentComputer >::GreedySegmentation ( )

inline

Default constructor.

Nb: not valid

Definition at line 385 of file GreedySegmentation.h.

{};

GreedySegmentation() [2/3]

template<typename TSegmentComputer >

DGtal::GreedySegmentation< TSegmentComputer >::GreedySegmentation	(	const ConstIterator &	itb,
		const ConstIterator &	ite,
		const SegmentComputer &	aSegmentComputer )

Constructor.

Parameters

itb	begin iterator of the underlying range
ite	end iterator of the underlying range
aSegmentComputer	an online segment recognition algorithm.

~GreedySegmentation()

template<typename TSegmentComputer >

DGtal::GreedySegmentation< TSegmentComputer >::~GreedySegmentation

(

)

Destructor.

GreedySegmentation() [3/3]

template<typename TSegmentComputer >

DGtal::GreedySegmentation< TSegmentComputer >::GreedySegmentation ( const GreedySegmentation< TSegmentComputer > & other )

private

Copy constructor.

Parameters

other

the object to clone.

Member Function Documentation

begin()

template<typename TSegmentComputer >

GreedySegmentation::SegmentComputerIterator DGtal::GreedySegmentation< TSegmentComputer >::begin

(

)

const

ConstIterator service.

Returns

an iterator pointing on the first segment.

BOOST_CONCEPT_ASSERT()

template<typename TSegmentComputer >

DGtal::GreedySegmentation< TSegmentComputer >::BOOST_CONCEPT_ASSERT

(

(concepts::CForwardSegmentComputer< TSegmentComputer >)

)

end()

template<typename TSegmentComputer >

GreedySegmentation::SegmentComputerIterator DGtal::GreedySegmentation< TSegmentComputer >::end

(

)

const

ConstIterator service.

Returns

an iterator pointing after the last segment.

isValid()

template<typename TSegmentComputer >

bool DGtal::GreedySegmentation< TSegmentComputer >::isValid

(

)

const

Checks the validity/consistency of the object.

Returns

'true' if the object is valid, 'false' otherwise.

operator=()

template<typename TSegmentComputer >

GreedySegmentation & DGtal::GreedySegmentation< TSegmentComputer >::operator= ( const GreedySegmentation< TSegmentComputer > & other )

private

Assignment.

Parameters

other

the object to copy.

Returns

a reference on 'this'.

selfDisplay()

template<typename TSegmentComputer >

void DGtal::GreedySegmentation< TSegmentComputer >::selfDisplay

(

std::ostream &

out

)

const

Writes/Displays the object on an output stream.

Parameters

out	the output stream where the object is written.

setMode()

template<typename TSegmentComputer >

void DGtal::GreedySegmentation< TSegmentComputer >::setMode

(

const std::string &

aMode

)

Set processing mode

Parameters

aMode

one of the 3 available modes : "Truncate" (default), "Truncate+1", "DoNotTruncate".

setSubRange()

template<typename TSegmentComputer >

void DGtal::GreedySegmentation< TSegmentComputer >::setSubRange	(	const ConstIterator &	itb,
		const ConstIterator &	ite )

Set a sub-range to process.

Parameters

itb	begin iterator the range to processed
ite	end iterator the range to processed

Nb: must be a valid range included in the underlying range.

Field Documentation

myBegin

template<typename TSegmentComputer >

ConstIterator DGtal::GreedySegmentation< TSegmentComputer >::myBegin

private

Begin iterator of the underlying range

Definition at line 454 of file GreedySegmentation.h.

myEnd

template<typename TSegmentComputer >

ConstIterator DGtal::GreedySegmentation< TSegmentComputer >::myEnd

private

End iterator of the underlying range

Definition at line 459 of file GreedySegmentation.h.

myMode

template<typename TSegmentComputer >

std::string DGtal::GreedySegmentation< TSegmentComputer >::myMode

private

Mode: either "Truncate" (default), "Truncate+1", or "DoNotTruncate".

Definition at line 474 of file GreedySegmentation.h.

mySegmentComputer

template<typename TSegmentComputer >

SegmentComputer DGtal::GreedySegmentation< TSegmentComputer >::mySegmentComputer

private

the segment computer.

Definition at line 479 of file GreedySegmentation.h.

myStart

template<typename TSegmentComputer >

ConstIterator DGtal::GreedySegmentation< TSegmentComputer >::myStart

private

Begin iterator of the subrange to segment

Definition at line 464 of file GreedySegmentation.h.

myStop

template<typename TSegmentComputer >

ConstIterator DGtal::GreedySegmentation< TSegmentComputer >::myStop

private

End iterator of the subrange to segment

Definition at line 469 of file GreedySegmentation.h.

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

• GreedySegmentation.h