cv::xfeatures2d::FREAK Class Reference

Class implementing the FREAK (Fast Retina Keypoint) keypoint descriptor, described in [8] . More...

#include <opencv2/xfeatures2d.hpp>

Inheritance diagram for cv::xfeatures2d::FREAK:

Collaboration diagram for cv::xfeatures2d::FREAK:

Public Member Functions
String	getDefaultName () const CV_OVERRIDE
virtual int	getNOctaves () const =0
virtual bool	getOrientationNormalized () const =0
virtual double	getPatternScale () const =0
virtual bool	getScaleNormalized () const =0
virtual void	setNOctaves (int nOctaves)=0
virtual void	setOrientationNormalized (bool orientationNormalized)=0
virtual void	setPatternScale (double patternScale)=0
virtual void	setScaleNormalized (bool scaleNormalized)=0
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 void	read (const FileNode &) CV_OVERRIDE
	Reads algorithm parameters from a file storage.
void	read (const String &fileName)
void	write (const Ptr< FileStorage > &fs, const String &name) const
void	write (const String &fileName) const
virtual void	write (FileStorage &) const CV_OVERRIDE
	Stores algorithm parameters in a file storage.
void	write (FileStorage &fs, const String &name) const
Public Member Functions inherited from cv::Algorithm
	Algorithm ()
virtual	~Algorithm ()
virtual void	clear ()
	Clears the algorithm state.
virtual void	save (const String &filename) const
void	write (const Ptr< FileStorage > &fs, const String &name=String()) const
void	write (FileStorage &fs, const String &name) const

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.
template<typename _Tp >
static Ptr< _Tp >	loadFromString (const String &strModel, const String &objname=String())
	Loads algorithm from a String.
template<typename _Tp >
static Ptr< _Tp >	read (const FileNode &fn)
	Reads algorithm from the file node.

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

Additional Inherited Members
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 [8] .

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

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:
	cv.xfeatures2d.FREAK.create(	[, orientationNormalized[, scaleNormalized[, patternScale[, nOctaves[, selectedPairs]]]]]	) ->	retval
	cv.xfeatures2d.FREAK_create(	[, orientationNormalized[, scaleNormalized[, patternScale[, nOctaves[, selectedPairs]]]]]	) ->	retval

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,

getDefaultName()

String cv::xfeatures2d::FREAK::getDefaultName ( ) const

virtual

Python:
	cv.xfeatures2d.FREAK.getDefaultName(		) ->	retval

Returns the algorithm string identifier. This string is used as top level xml/yml node tag when the object is saved to a file or string.

Reimplemented from cv::Feature2D.

getNOctaves()

virtual int cv::xfeatures2d::FREAK::getNOctaves ( ) const

pure virtual

Python:
	cv.xfeatures2d.FREAK.getNOctaves(		) ->	retval

getOrientationNormalized()

virtual bool cv::xfeatures2d::FREAK::getOrientationNormalized ( ) const

pure virtual

Python:
	cv.xfeatures2d.FREAK.getOrientationNormalized(		) ->	retval

getPatternScale()

virtual double cv::xfeatures2d::FREAK::getPatternScale ( ) const

pure virtual

Python:
	cv.xfeatures2d.FREAK.getPatternScale(		) ->	retval

getScaleNormalized()

virtual bool cv::xfeatures2d::FREAK::getScaleNormalized ( ) const

pure virtual

Python:
	cv.xfeatures2d.FREAK.getScaleNormalized(		) ->	retval

setNOctaves()

virtual void cv::xfeatures2d::FREAK::setNOctaves ( int  nOctaves )

pure virtual

Python:
	cv.xfeatures2d.FREAK.setNOctaves(	nOctaves	) ->	None

setOrientationNormalized()

virtual void cv::xfeatures2d::FREAK::setOrientationNormalized ( bool  orientationNormalized )

pure virtual

Python:
	cv.xfeatures2d.FREAK.setOrientationNormalized(	orientationNormalized	) ->	None

setPatternScale()

virtual void cv::xfeatures2d::FREAK::setPatternScale ( double  patternScale )

pure virtual

Python:
	cv.xfeatures2d.FREAK.setPatternScale(	patternScale	) ->	None

setScaleNormalized()

virtual void cv::xfeatures2d::FREAK::setScaleNormalized ( bool  scaleNormalized )

pure virtual

Python:
	cv.xfeatures2d.FREAK.setScaleNormalized(	scaleNormalized	) ->	None

Member Data Documentation

NB_ORIENPAIRS

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

static

NB_PAIRS

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

static

NB_SCALES

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

static

---

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

• opencv2/xfeatures2d.hpp