Brute-force descriptor matcher. More...

#include <opencv2/features.hpp>

Collaboration diagram for cv::BFMatcher:

Public Member Functions
	BFMatcher (int normType=NORM_L2, bool crossCheck=false)
	Brute-force matcher constructor (obsolete). Please use BFMatcher.create()

virtual	~BFMatcher ()

virtual CV_NODISCARD_STD Ptr< DescriptorMatcher >	clone (bool emptyTrainData=false) const CV_OVERRIDE
	Clones the matcher.

virtual bool	isMaskSupported () const CV_OVERRIDE
	Returns true if the descriptor matcher supports masking permissible matches.

Public Member Functions inherited from cv::DescriptorMatcher
virtual	~DescriptorMatcher ()

virtual void	add (InputArrayOfArrays descriptors)
	Adds descriptors to train a CPU(trainDescCollectionis) or GPU(utrainDescCollectionis) descriptor collection.

virtual void	clear () CV_OVERRIDE
	Clears the train descriptor collections.

virtual bool	empty () const CV_OVERRIDE
	Returns true if there are no train descriptors in the both collections.

const std::vector< Mat > &	getTrainDescriptors () const
	Returns a constant link to the train descriptor collection trainDescCollection .

void	knnMatch (InputArray queryDescriptors, InputArray trainDescriptors, std::vector< std::vector< DMatch > > &matches, int k, InputArray mask=noArray(), bool compactResult=false) const
	Finds the k best matches for each descriptor from a query set.

void	knnMatch (InputArray queryDescriptors, std::vector< std::vector< DMatch > > &matches, int k, InputArrayOfArrays masks=noArray(), bool compactResult=false)

void	match (InputArray queryDescriptors, InputArray trainDescriptors, std::vector< DMatch > &matches, InputArray mask=noArray()) const
	Finds the best match for each descriptor from a query set.

void	match (InputArray queryDescriptors, std::vector< DMatch > &matches, InputArrayOfArrays masks=noArray())

void	radiusMatch (InputArray queryDescriptors, InputArray trainDescriptors, std::vector< std::vector< DMatch > > &matches, float maxDistance, InputArray mask=noArray(), bool compactResult=false) const
	For each query descriptor, finds the training descriptors not farther than the specified distance.

void	radiusMatch (InputArray queryDescriptors, std::vector< std::vector< DMatch > > &matches, float maxDistance, InputArrayOfArrays masks=noArray(), bool compactResult=false)

virtual void	read (const FileNode &) CV_OVERRIDE
	Reads algorithm parameters from a file storage.

void	read (const String &fileName)

virtual void	train ()
	Trains a descriptor matcher.

void	write (const Ptr< FileStorage > &fs, const String &name) const

void	write (const String &fileName) const

virtual void	write (FileStorage &) const CV_OVERRIDE
	Stores algorithm parameters in a file storage.

void	write (FileStorage &fs, const String &name) const

Public Member Functions inherited from cv::Algorithm
	Algorithm ()

virtual	~Algorithm ()

virtual String	getDefaultName () const

virtual void	save (const String &filename) const

void	write (const Ptr< FileStorage > &fs, const String &name=String()) const

void	write (FileStorage &fs, const String &name) const

Static Public Member Functions
static Ptr< BFMatcher >	create (int normType=NORM_L2, bool crossCheck=false)
	Brute-force matcher create method.

Static Public Member Functions inherited from cv::DescriptorMatcher
static Ptr< DescriptorMatcher >	create (const DescriptorMatcher::MatcherType &matcherType)

static Ptr< DescriptorMatcher >	create (const String &descriptorMatcherType)
	Creates a descriptor matcher of a given type with the default parameters (using default constructor).

Static Public Member Functions inherited from cv::Algorithm
template<typename _Tp >
static Ptr< _Tp >	load (const String &filename, const String &objname=String())
	Loads algorithm from the file.

template<typename _Tp >
static Ptr< _Tp >	loadFromString (const String &strModel, const String &objname=String())
	Loads algorithm from a String.

template<typename _Tp >
static Ptr< _Tp >	read (const FileNode &fn)
	Reads algorithm from the file node.

Protected Member Functions
virtual void	knnMatchImpl (InputArray queryDescriptors, std::vector< std::vector< DMatch > > &matches, int k, InputArrayOfArrays masks=noArray(), bool compactResult=false) CV_OVERRIDE

virtual void	radiusMatchImpl (InputArray queryDescriptors, std::vector< std::vector< DMatch > > &matches, float maxDistance, InputArrayOfArrays masks=noArray(), bool compactResult=false) CV_OVERRIDE

Protected Member Functions inherited from cv::DescriptorMatcher
void	checkMasks (InputArrayOfArrays masks, int queryDescriptorsCount) const

Protected Member Functions inherited from cv::Algorithm
void	writeFormat (FileStorage &fs) const

Protected Attributes
bool	crossCheck

int	normType

Protected Attributes inherited from cv::DescriptorMatcher
std::vector< Mat >	trainDescCollection
	Collection of descriptors from train images.

std::vector< UMat >	utrainDescCollection

Additional Inherited Members
Public Types inherited from cv::DescriptorMatcher
enum	MatcherType { FLANNBASED = 1 , BRUTEFORCE = 2 , BRUTEFORCE_L1 = 3 , BRUTEFORCE_HAMMING = 4 , BRUTEFORCE_HAMMINGLUT = 5 , BRUTEFORCE_SL2 = 6 }

Static Protected Member Functions inherited from cv::DescriptorMatcher
static CV_NODISCARD_STD Mat	clone_op (Mat m)

static bool	isMaskedOut (InputArrayOfArrays masks, int queryIdx)

static bool	isPossibleMatch (InputArray mask, int queryIdx, int trainIdx)

Detailed Description

Brute-force descriptor matcher.

For each descriptor in the first set, this matcher finds the closest descriptor in the second set by trying each one. This descriptor matcher supports masking permissible matches of descriptor sets.

Constructor & Destructor Documentation

◆ BFMatcher()

cv::BFMatcher::BFMatcher	(	int	normType = `NORM_L2`,
		bool	crossCheck = `false`
	)

Python:
	cv.BFMatcher(	[, normType[, crossCheck]]	) ->	<BFMatcher object>

Brute-force matcher constructor (obsolete). Please use BFMatcher.create()

◆ ~BFMatcher()

virtual cv::BFMatcher::~BFMatcher ( )

inlinevirtual

Member Function Documentation

◆ clone()

virtual CV_NODISCARD_STD Ptr< DescriptorMatcher > cv::BFMatcher::clone ( bool emptyTrainData = false ) const

virtual

Clones the matcher.

Parameters

emptyTrainData If emptyTrainData is false, the method creates a deep copy of the object, that is, copies both parameters and train data. If emptyTrainData is true, the method creates an object copy with the current parameters but with empty train data.

Implements cv::DescriptorMatcher.

◆ create()

static Ptr< BFMatcher > cv::BFMatcher::create	(	int	normType = `NORM_L2`,
		bool	crossCheck = `false`
	)

static

Python:
	cv.BFMatcher.create(	[, normType[, crossCheck]]	) ->	retval
	cv.BFMatcher_create(	[, normType[, crossCheck]]	) ->	retval

Brute-force matcher create method.

Parameters

normType One of NORM_L1, NORM_L2, NORM_HAMMING, NORM_HAMMING2. L1 and L2 norms are preferable choices for SIFT and SURF descriptors, NORM_HAMMING should be used with ORB, BRISK and BRIEF, NORM_HAMMING2 should be used with ORB when WTA_K==3 or 4 (see ORB::ORB constructor description).

crossCheck If it is false, this is will be default BFMatcher behaviour when it finds the k nearest neighbors for each query descriptor. If crossCheck==true, then the knnMatch() method with k=1 will only return pairs (i,j) such that for i-th query descriptor the j-th descriptor in the matcher's collection is the nearest and vice versa, i.e. the BFMatcher will only return consistent pairs. Such technique usually produces best results with minimal number of outliers when there are enough matches. This is alternative to the ratio test, used by D. Lowe in SIFT paper.

◆ isMaskSupported()

virtual bool cv::BFMatcher::isMaskSupported ( ) const

inlinevirtual

Returns true if the descriptor matcher supports masking permissible matches.

Implements cv::DescriptorMatcher.

◆ knnMatchImpl()

virtual void cv::BFMatcher::knnMatchImpl	(	InputArray	queryDescriptors,
		std::vector< std::vector< DMatch > > &	matches,
		int	k,
		InputArrayOfArrays	masks = `noArray()`,
		bool	compactResult = `false`
	)

protectedvirtual

In fact the matching is implemented only by the following two methods. These methods suppose that the class object has been trained already. Public match methods call these methods after calling train().

Implements cv::DescriptorMatcher.

◆ radiusMatchImpl()

virtual void cv::BFMatcher::radiusMatchImpl	(	InputArray	queryDescriptors,
		std::vector< std::vector< DMatch > > &	matches,
		float	maxDistance,
		InputArrayOfArrays	masks = `noArray()`,
		bool	compactResult = `false`
	)

protectedvirtual

Implements cv::DescriptorMatcher.

Member Data Documentation

◆ crossCheck

bool cv::BFMatcher::crossCheck

protected

◆ normType

int cv::BFMatcher::normType

protected

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

opencv2/features.hpp

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ BFMatcher()

◆ ~BFMatcher()

Member Function Documentation

◆ clone()

◆ create()

◆ isMaskSupported()

◆ knnMatchImpl()

◆ radiusMatchImpl()

Member Data Documentation

◆ crossCheck

◆ normType