Experimental 2D Features Algorithms#

Detailed Description#

This section describes experimental algorithms for 2d feature detection.

Classes#

Name

Description

class cv::xfeatures2d::AffineFeature2D

Class implementing affine adaptation for key points. View details

class cv::xfeatures2d::AgastFeatureDetector

Wrapping class for feature detection using the AGAST method. : View details

class cv::xfeatures2d::AKAZE

Class implementing the AKAZE keypoint detector and descriptor extractor, described in [12]. View details

class cv::xfeatures2d::BEBLID

Class implementing BEBLID (Boosted Efficient Binary Local Image Descriptor), described in [288] . View details

class cv::xfeatures2d::BoostDesc

Class implementing BoostDesc (Learning Image Descriptors with Boosting), described in [294] and [295]. View details

class cv::xfeatures2d::BriefDescriptorExtractor

Class for computing BRIEF descriptors described in [53] . View details

class cv::xfeatures2d::BRISK

Class implementing the BRISK keypoint detector and descriptor extractor, described in [177] . View details

class cv::xfeatures2d::DAISY

Class implementing DAISY descriptor, described in [304]. View details

class cv::xfeatures2d::Elliptic_KeyPoint

Elliptic region around an interest point. View details

class cv::xfeatures2d::FREAK

Class implementing the FREAK (Fast Retina Keypoint) keypoint descriptor, described in [10] . View details

class cv::xfeatures2d::HarrisLaplaceFeatureDetector

Class implementing the Harris-Laplace feature detector as described in [214]. View details

class cv::xfeatures2d::KAZE

Class implementing the KAZE keypoint detector and descriptor extractor, described in [11] . View details

class cv::xfeatures2d::LATCH

View details

class cv::xfeatures2d::LUCID

Class implementing the locally uniform comparison image descriptor, described in [360]. View details

class cv::xfeatures2d::MSDDetector

Class implementing the MSD (Maximal Self-Dissimilarity) keypoint detector, described in [305]. View details

class cv::xfeatures2d::PCTSignatures

Class implementing PCT (position-color-texture) signature extraction as described in [171]. The algorithm is divided to a feature sampler and a clusterizer. Feature sampler produces samples at given set of coordinates. Clusterizer then produces clusters of these samples using k-means algorithm. Resulting set of clusters is the signature of the input image. View details

class cv::xfeatures2d::PCTSignaturesSQFD

Class implementing Signature Quadratic Form Distance (SQFD). View details

class cv::xfeatures2d::StarDetector

The class implements the keypoint detector introduced by [3], synonym of StarDetector. : View details

class cv::xfeatures2d::TBMR

Class implementing the Tree Based Morse Regions (TBMR) as described in [344] extended with scaled extraction ability. View details

class cv::xfeatures2d::TEBLID

Class implementing TEBLID (Triplet-based Efficient Binary Local Image Descriptor), described in [289]. View details

class cv::xfeatures2d::VGG

Class implementing VGG (Oxford Visual Geometry Group) descriptor trained end to end using “Descriptor Learning Using Convex Optimisation” (DLCO) aparatus described in [275]. View details

Function Documentation#

AGAST()#

void cv::xfeatures2d::AGAST(
InputArray image,
std::vector< KeyPoint > & keypoints,
int threshold,
bool nonmaxSuppression = true,
AgastFeatureDetector::DetectorType type = AgastFeatureDetector::OAST_9_16 )

#include <opencv2/xfeatures2d.hpp>

Detects corners using the AGAST algorithm.

For non-Intel platforms, there is a tree optimised variant of AGAST with same numerical results. The 32-bit binary tree tables were generated automatically from original code using perl script. The perl script and examples of tree generation are placed in features2d/doc folder. Detects corners using the AGAST algorithm by [201] .

Parameters

FASTForPointSet()#

void cv::xfeatures2d::FASTForPointSet(
InputArray image,
std::vector< KeyPoint > & keypoints,
int threshold,
bool nonmaxSuppression = true,
cv::FastFeatureDetector::DetectorType type = FastFeatureDetector::TYPE_9_16 )

#include <opencv2/xfeatures2d.hpp>

Estimates cornerness for prespecified KeyPoints using the FAST algorithm.

Detects corners using the FAST algorithm by [253] .

Parameters

  • image — grayscale image where keypoints (corners) are detected.

  • keypoints — keypoints which should be tested to fit the FAST criteria. Keypoints not being detected as corners are removed.

  • threshold — threshold on difference between intensity of the central pixel and pixels of a circle around this pixel.

  • nonmaxSuppression — if true, non-maximum suppression is applied to detected corners (keypoints).

  • type — one of the three neighborhoods as defined in the paper: FastFeatureDetector::TYPE_9_16, FastFeatureDetector::TYPE_7_12, FastFeatureDetector::TYPE_5_8