rtabmap::VisualWord Class Reference

Represents a visual word (feature descriptor) used in the bag-of-words (BoW) model. More...

#include <VisualWord.h>

Public Member Functions
	VisualWord (int id, const cv::Mat &descriptor, int signatureId=0)
	Constructor.
	~VisualWord ()
	Destructor.
void	addRef (int signatureId)
	Adds a reference to this word for the given signature ID.
int	removeAllRef (int signatureId)
	Removes all references to this word for the given signature ID.
unsigned long	getMemoryUsed () const
	Estimates the memory used by this visual word in bytes.
int	getTotalReferences () const
	Returns the total number of references (across all signatures).
int	id () const
	Returns the ID of this visual word.
const cv::Mat &	getDescriptor () const
	Returns the feature descriptor of this word.
const std::map< int, int > &	getReferences () const
	Returns the references of this word.
bool	isSaved () const
	Checks if the word has been saved to the database.
void	setSaved (bool saved)
	Sets the saved flag for the word.

Detailed Description

Represents a visual word (feature descriptor) used in the bag-of-words (BoW) model.

A VisualWord holds a unique identifier, its descriptor (usually a feature vector from an image), and a record of where (in which signatures/images) it was observed. This is a key component in loop closure detection and visual place recognition in RTAB-Map.

The word keeps track of references (signature IDs) where it appears, and how many times it was observed in each signature. It also tracks whether the word has been saved to a database.

Definition at line 49 of file VisualWord.h.

Constructor & Destructor Documentation

VisualWord()

rtabmap::VisualWord::VisualWord	(	int	id,
		const cv::Mat &	descriptor,
		int	signatureId = 0
	)

Constructor.

Parameters

id	Unique ID of the visual word.
descriptor	The descriptor associated with the word (e.g., ORB, SIFT).
signatureId	Optional signature ID where the word is first observed.

Member Function Documentation

addRef()

void rtabmap::VisualWord::addRef

(

int

signatureId

)

Adds a reference to this word for the given signature ID.

Parameters

signatureId

ID of the signature in which this word is observed.

removeAllRef()

int rtabmap::VisualWord::removeAllRef

(

int

signatureId

)

Removes all references to this word for the given signature ID.

Parameters

signatureId

ID of the signature from which references will be removed.

Returns

Number of references removed.

getMemoryUsed()

unsigned long rtabmap::VisualWord::getMemoryUsed

(

)

const

Estimates the memory used by this visual word in bytes.

Returns

Size in bytes.

getTotalReferences()

int rtabmap::VisualWord::getTotalReferences ( ) const

inline

Returns the total number of references (across all signatures).

Returns

Number of total references.

Definition at line 88 of file VisualWord.h.

id()

int rtabmap::VisualWord::id ( ) const

inline

Returns the ID of this visual word.

Returns

Word ID.

Definition at line 94 of file VisualWord.h.

getDescriptor()

const cv::Mat & rtabmap::VisualWord::getDescriptor ( ) const

inline

Returns the feature descriptor of this word.

Returns

The OpenCV matrix descriptor.

Definition at line 100 of file VisualWord.h.

getReferences()

const std::map< int, int > & rtabmap::VisualWord::getReferences ( ) const

inline

Returns the references of this word.

Returns

A map of (signature ID, occurrence count).

Definition at line 106 of file VisualWord.h.

isSaved()

bool rtabmap::VisualWord::isSaved ( ) const

inline

Checks if the word has been saved to the database.

Returns

True if saved, false otherwise.

Definition at line 112 of file VisualWord.h.

setSaved()

void rtabmap::VisualWord::setSaved ( bool  saved )

inline

Sets the saved flag for the word.

Parameters

saved

True if the word has been saved to the database.

Definition at line 118 of file VisualWord.h.

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

• corelib/include/rtabmap/core/VisualWord.h