Class cv::xfeatures2d::FREAK#

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

#include <opencv2/xfeatures2d.hpp>

Collaboration diagram for cv::xfeatures2d::FREAK:

Public Member Functions#

Public Member Functions inherited from cv::Feature2D

Return	Name	Description
	`~Feature2D()`
`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).
`void`	`compute(` `InputArrayOfArrays images,` `std::vector< std::vector< KeyPoint > > & keypoints,` `OutputArrayOfArrays descriptors )`
`int`	`defaultNorm()`
`int`	`descriptorSize()`
`int`	`descriptorType()`
`void`	`detect(` `InputArray image,` `std::vector< KeyPoint > & keypoints,` `InputArray mask = noArray() )`	Detects keypoints in an image (first variant) or image set (second variant).
`void`	`detect(` `InputArrayOfArrays images,` `std::vector< std::vector< KeyPoint > > & keypoints,` `InputArrayOfArrays masks = noArray() )`
`void`	`detectAndCompute(` `InputArray image,` `InputArray mask,` `std::vector< KeyPoint > & keypoints,` `OutputArray descriptors,` `bool useProvidedKeypoints = false )`
`bool`	`empty()`	Return true if detector object is empty.
`String`	`getDefaultName()`
`void`	`read(const FileNode & fn)`	Reads algorithm parameters from a file storage.
`void`	`read(const String & fileName)`
`void`	`write(const String & fileName)`
`void`	`write(FileStorage & fs)`	Stores algorithm parameters in a file storage.
`void`	`write(` `FileStorage & fs,` `const String & name )`

Public Member Functions inherited from cv::Algorithm

Return	Name	Description
	`Algorithm()`
	`~Algorithm()`
`void`	`clear()`	Clears the algorithm state.
`bool`	`empty()`	Returns true if the Algorithm is empty (e.g. in the very beginning or after unsuccessful read.
`String`	`getDefaultName()`
`void`	`read(const FileNode & fn)`	Reads algorithm parameters from a file storage.
`void`	`save(const String & filename)`
`void`	`write(` `const Ptr< FileStorage > & fs,` `const String & name = String() )`
`void`	`write(FileStorage & fs)`	Stores algorithm parameters in a file storage.
`void`	`write(` `FileStorage & fs,` `const String & name )`

Static Public Member Functions#

Static Public Member Functions inherited from cv::Algorithm

Return	Name	Description
`static Ptr< _Tp >`	`load(` `const String & filename,` `const String & objname = String() )`	Loads algorithm from the file.
`static Ptr< _Tp >`	`loadFromString(` `const String & strModel,` `const String & objname = String() )`	Loads algorithm from a String.
`static Ptr< _Tp >`	`read(const FileNode & fn)`	Reads algorithm from the file node.

Additional Inherited Members#

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#

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 >() )

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()

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.

getNOctaves()#

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

getOrientationNormalized()#

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

getPatternScale()#

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

getScaleNormalized()#

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

setNOctaves()#

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

setOrientationNormalized()#

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

setPatternScale()#

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

setScaleNormalized()#

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

Member Data Documentation#

NB_ORIENPAIRS#

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

NB_PAIRS#

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

NB_SCALES#

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

Source file#

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

opencv2/xfeatures2d.hpp