Class implementing the FREAK (Fast Retina Keypoint) keypoint descriptor, described in [4] . More...

#include <opencv2/xfeatures2d.hpp>

Inheritance diagram for cv::xfeatures2d::FREAK:

Public Types
enum	{ NB_SCALES = 64, NB_PAIRS = 512, NB_ORIENPAIRS = 45 }

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 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...

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). More...

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). More...

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. More...

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. More...

void	write (const String &fileName) const

virtual void	write (FileStorage &) const CV_OVERRIDE
	Stores algorithm parameters in a file storage. More...

void	write (const Ptr< FileStorage > &fs, const String &name=String()) const

Public Member Functions inherited from cv::Algorithm
	Algorithm ()

virtual	~Algorithm ()

virtual void	clear ()
	Clears the algorithm state. More...

virtual void	save (const String &filename) const

void	write (const Ptr< FileStorage > &fs, const String &name=String()) const
	simplified API for language bindings This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...

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 [4] .

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 Enumeration Documentation

◆ anonymous enum

anonymous enum

Enumerator
NB_SCALES
NB_PAIRS
NB_ORIENPAIRS

Member Function Documentation

◆ create()

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,

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

opencv2/xfeatures2d.hpp

Public Types

Static Public Member Functions

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ anonymous enum

Member Function Documentation

◆ create()