OpenCV  3.3.0-dev
Open Source Computer Vision
Public Member Functions | Static Public Member Functions | Protected Member Functions | Protected Attributes | List of all members
cv::BFMatcher Class Reference

Brute-force descriptor matcher. More...

#include "features2d.hpp"

Inheritance diagram for cv::BFMatcher:
cv::DescriptorMatcher cv::Algorithm

Public Member Functions

 BFMatcher (int normType=NORM_L2, bool crossCheck=false)
 Brute-force matcher constructor (obsolete). Please use BFMatcher.create() More...
 
virtual ~BFMatcher ()
 
virtual Ptr< DescriptorMatcherclone (bool emptyTrainData=false) const
 Clones the matcher. More...
 
virtual bool isMaskSupported () const
 Returns true if the descriptor matcher supports masking permissible matches. More...
 
- 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. More...
 
virtual void clear ()
 Clears the train descriptor collections. More...
 
virtual bool empty () const
 Returns true if there are no train descriptors in the both collections. More...
 
const std::vector< Mat > & getTrainDescriptors () const
 Returns a constant link to the train descriptor collection trainDescCollection . More...
 
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. More...
 
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. More...
 
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. More...
 
void radiusMatch (InputArray queryDescriptors, std::vector< std::vector< DMatch > > &matches, float maxDistance, InputArrayOfArrays masks=noArray(), bool compactResult=false)
 
void read (const String &fileName)
 
virtual void read (const FileNode &)
 Reads algorithm parameters from a file storage. More...
 
virtual void train ()
 Trains a descriptor matcher. More...
 
void write (const String &fileName) const
 
virtual void write (FileStorage &) const
 Stores algorithm parameters in a file storage. More...
 
- Public Member Functions inherited from cv::Algorithm
 Algorithm ()
 
virtual ~Algorithm ()
 
virtual String getDefaultName () const
 
virtual void save (const String &filename) const
 

Static Public Member Functions

static Ptr< BFMatchercreate (int normType=NORM_L2, bool crossCheck=false)
 Brute-force matcher create method. More...
 
- Static Public Member Functions inherited from cv::DescriptorMatcher
static Ptr< DescriptorMatchercreate (const String &descriptorMatcherType)
 Creates a descriptor matcher of a given type with the default parameters (using default constructor). More...
 
static Ptr< DescriptorMatchercreate (int matcherType)
 
- 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. More...
 
template<typename _Tp >
static Ptr< _Tp > loadFromString (const String &strModel, const String &objname=String())
 Loads algorithm from a String. More...
 
template<typename _Tp >
static Ptr< _Tp > read (const FileNode &fn)
 Reads algorithm from the file node. More...
 

Protected Member Functions

virtual void knnMatchImpl (InputArray queryDescriptors, std::vector< std::vector< DMatch > > &matches, int k, InputArrayOfArrays masks=noArray(), bool compactResult=false)
 
virtual void radiusMatchImpl (InputArray queryDescriptors, std::vector< std::vector< DMatch > > &matches, float maxDistance, InputArrayOfArrays masks=noArray(), bool compactResult=false)
 
- 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< MattrainDescCollection
 Collection of descriptors from train images. More...
 
std::vector< UMatutrainDescCollection
 

Additional Inherited Members

- Public Types inherited from cv::DescriptorMatcher
enum  {
  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 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 
)

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

§ ~BFMatcher()

virtual cv::BFMatcher::~BFMatcher ( )
inlinevirtual

Member Function Documentation

§ clone()

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

Clones the matcher.

Parameters
emptyTrainDataIf 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

Brute-force matcher create method.

Parameters
normTypeOne 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).
crossCheckIf 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: