BFMatcher

Objective-C

@interface BFMatcher : DescriptorMatcher

Swift

class BFMatcher : DescriptorMatcher

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.

Member of Features2d

Methods

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

    Declaration

    Objective-C

    - (nonnull instancetype)initWithNormType:(NormTypes)normType
                              crossCheck:(BOOL)crossCheck;

    Swift

    init(normType: NormTypes, crossCheck: Bool)

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

    Declaration

    Objective-C

    - (nonnull instancetype)initWithNormType:(NormTypes)normType;

    Swift

    init(normType: NormTypes)

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

    Declaration

    Objective-C

    - (nonnull instancetype)init;

    Swift

    init()

  • Brute-force matcher create method.

    Declaration

    Objective-C

    + (nonnull BFMatcher *)createBFMatcher:(NormTypes)normType
                            crossCheck:(BOOL)crossCheck;

    Swift

    class func create(normType: NormTypes, crossCheck: Bool) -> BFMatcher

    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.

  • Brute-force matcher create method.

    Declaration

    Objective-C

    + (nonnull BFMatcher *)createBFMatcher:(NormTypes)normType;

    Swift

    class func create(normType: NormTypes) -> BFMatcher

    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). 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.

  • Brute-force matcher create method. 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). 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.

    Declaration

    Objective-C

    + (nonnull BFMatcher *)createBFMatcher;

    Swift

    class func create() -> BFMatcher