# Package org.opencv.xfeatures2d

- Class Summary
  Class | Description
  --- | ---
  BoostDesc | Class implementing BoostDesc (Learning Image Descriptors with Boosting), described in CITE: Trzcinski13a and CITE: Trzcinski13b.
  BriefDescriptorExtractor | Class for computing BRIEF descriptors described in CITE: calon2010 .
  DAISY | Class implementing DAISY descriptor, described in CITE: Tola10 radius radius of the descriptor at the initial scale q_radius amount of radial range division quantity q_theta amount of angular range division quantity q_hist amount of gradient orientations range division quantity norm choose descriptors normalization type, where DAISY::NRM_NONE will not do any normalization (default), DAISY::NRM_PARTIAL mean that histograms are normalized independently for L2 norm equal to 1.0, DAISY::NRM_FULL mean that descriptors are normalized for L2 norm equal to 1.0, DAISY::NRM_SIFT mean that descriptors are normalized for L2 norm equal to 1.0 but no individual one is bigger than 0.154 as in SIFT H optional 3x3 homography matrix used to warp the grid of daisy but sampling keypoints remains unwarped on image interpolation switch to disable interpolation for speed improvement at minor quality loss use_orientation sample patterns using keypoints orientation, disabled by default.
  FREAK | Class implementing the FREAK (*Fast Retina Keypoint*) keypoint descriptor, described in CITE: AOV12 .
  HarrisLaplaceFeatureDetector | Class implementing the Harris-Laplace feature detector as described in CITE: Mikolajczyk2004.
  LATCH | latch Class for computing the LATCH descriptor.
  LUCID | Class implementing the locally uniform comparison image descriptor, described in CITE: LUCID An image descriptor that can be computed very fast, while being about as robust as, for example, SURF or BRIEF.
  MSDDetector | Class implementing the MSD (*Maximal Self-Dissimilarity*) keypoint detector, described in CITE: Tombari14.
  PCTSignatures | Class implementing PCT (position-color-texture) signature extraction as described in CITE: KrulisLS16.
  PCTSignaturesSQFD | Class implementing Signature Quadratic Form Distance (SQFD).
  SIFT | Class for extracting keypoints and computing descriptors using the Scale Invariant Feature Transform (SIFT) algorithm by D.
  StarDetector | The class implements the keypoint detector introduced by CITE: Agrawal08, synonym of StarDetector.
  SURF | Class for extracting Speeded Up Robust Features from an image CITE: Bay06 .
  SURF_CUDA | Class used for extracting Speeded Up Robust Features (SURF) from an image.
  VGG | Class implementing VGG (Oxford Visual Geometry Group) descriptor trained end to end using "Descriptor Learning Using Convex Optimisation" (DLCO) aparatus described in CITE: Simonyan14.
  Xfeatures2d |