cv::xfeatures2d::FREAK Class Reference

Class implementing the FREAK (Fast Retina Keypoint) keypoint descriptor, described in. More...

#include <opencv2/xfeatures2d.hpp>

Inheritance diagram for cv::xfeatures2d::FREAK:

Static Public Member Functions
static Ptr< FREAK >	create (bool orientationNormalized=true, bool scaleNormalized=true, float patternScale=22.0f, int nOctaves=4, const std::vector< int > &selectedPairs=std::vector< int >())

Static Public Attributes
static const int	NB_ORIENPAIRS = 45
static const int	NB_PAIRS = 512
static const int	NB_SCALES = 64

Additional Inherited Members
Public Member Functions inherited from cv::Feature2D
virtual	~Feature2D ()
virtual void	compute (InputArray image, std::vector< KeyPoint > &keypoints, OutputArray descriptors)
	Computes the descriptors for a set of keypoints detected in an image (first variant) or image set (second variant).
virtual void	compute (InputArrayOfArrays images, std::vector< std::vector< KeyPoint > > &keypoints, OutputArrayOfArrays descriptors)
virtual int	defaultNorm () const
virtual int	descriptorSize () const
virtual int	descriptorType () const
virtual void	detect (InputArray image, std::vector< KeyPoint > &keypoints, InputArray mask=noArray())
	Detects keypoints in an image (first variant) or image set (second variant).
virtual void	detect (InputArrayOfArrays images, std::vector< std::vector< KeyPoint > > &keypoints, InputArrayOfArrays masks=noArray())
virtual void	detectAndCompute (InputArray image, InputArray mask, std::vector< KeyPoint > &keypoints, OutputArray descriptors, bool useProvidedKeypoints=false)
virtual bool	empty () const CV_OVERRIDE
	Return true if detector object is empty.
virtual String	getDefaultName () const CV_OVERRIDE
void	read (const String &fileName)
virtual void	read (const FileNode &) CV_OVERRIDE
	Reads algorithm parameters from a file storage.
void	write (const String &fileName) const
virtual void	write (FileStorage &) const CV_OVERRIDE
	Stores algorithm parameters in a file storage.
void	write (const Ptr< FileStorage > &fs, const String &name=String()) const
Protected Member Functions inherited from cv::Algorithm
void	writeFormat (FileStorage &fs) const

Detailed Description

Class implementing the FREAK (Fast Retina Keypoint) keypoint descriptor, described in.

AOV12 .

The algorithm propose a novel keypoint descriptor inspired by the human visual system and more precisely the retina, coined Fast Retina Key- point (FREAK). A cascade of binary strings is computed by efficiently comparing image intensities over a retinal sampling pattern. FREAKs are in general faster to compute with lower memory load and also more robust than SIFT, SURF or BRISK. They are competitive alternatives to existing keypoints in particular for embedded applications.

Note

• An example on how to use the FREAK descriptor can be found at opencv_source_code/samples/cpp/freak_demo.cpp

Member Function Documentation

static Ptr<FREAK> cv::xfeatures2d::FREAK::create ( bool  orientationNormalized = true, bool  scaleNormalized = true, float  patternScale = 22.0f, int  nOctaves = 4, const std::vector< int > &  selectedPairs = std::vector< int >()  )

static

Python:
	retval	=	cv.xfeatures2d.FREAK_create(	[, orientationNormalized[, scaleNormalized[, patternScale[, nOctaves[, selectedPairs]]]]]	)

Parameters

orientationNormalized	Enable orientation normalization.
scaleNormalized	Enable scale normalization.
patternScale	Scaling of the description pattern.
nOctaves	Number of octaves covered by the detected keypoints.
selectedPairs	(Optional) user defined selected pairs indexes,

Member Data Documentation

const int cv::xfeatures2d::FREAK::NB_ORIENPAIRS = 45

static

const int cv::xfeatures2d::FREAK::NB_PAIRS = 512

static

const int cv::xfeatures2d::FREAK::NB_SCALES = 64

static

---

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

• xfeatures2d.hpp