cv::Feature2D Class Reference

Abstract base class for 2D image feature detectors and descriptor extractors. More...

#include <opencv2/features2d.hpp>

Inheritance diagram for cv::Feature2D:

Public Member Functions
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...

Additional Inherited Members
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...
Protected Member Functions inherited from cv::Algorithm
void	writeFormat (FileStorage &fs) const

Detailed Description

Abstract base class for 2D image feature detectors and descriptor extractors.

Constructor & Destructor Documentation

~Feature2D()

virtual cv::Feature2D::~Feature2D ( )

virtual

Member Function Documentation

compute() [1/2]

virtual void cv::Feature2D::compute ( InputArray  image, std::vector< KeyPoint > &  keypoints, OutputArray  descriptors  )

virtual

Python:
	keypoints, descriptors	=	cv.Feature2D.compute(	image, keypoints[, descriptors]	)
	keypoints, descriptors	=	cv.Feature2D.compute(	images, keypoints[, descriptors]	)

Computes the descriptors for a set of keypoints detected in an image (first variant) or image set (second variant).

Parameters

image	Image.
keypoints	Input collection of keypoints. Keypoints for which a descriptor cannot be computed are removed. Sometimes new keypoints can be added, for example: SIFT duplicates keypoint with several dominant orientations (for each orientation).
descriptors	Computed descriptors. In the second variant of the method descriptors[i] are descriptors computed for a keypoints[i]. Row j is the keypoints (or keypoints[i]) is the descriptor for keypoint j-th keypoint.

Reimplemented in cv::xfeatures2d::DAISY.

compute() [2/2]

virtual void cv::Feature2D::compute ( InputArrayOfArrays  images, std::vector< std::vector< KeyPoint > > &  keypoints, OutputArrayOfArrays  descriptors  )

virtual

Python:
	keypoints, descriptors	=	cv.Feature2D.compute(	image, keypoints[, descriptors]	)
	keypoints, descriptors	=	cv.Feature2D.compute(	images, keypoints[, descriptors]	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

images	Image set.
keypoints	Input collection of keypoints. Keypoints for which a descriptor cannot be computed are removed. Sometimes new keypoints can be added, for example: SIFT duplicates keypoint with several dominant orientations (for each orientation).
descriptors	Computed descriptors. In the second variant of the method descriptors[i] are descriptors computed for a keypoints[i]. Row j is the keypoints (or keypoints[i]) is the descriptor for keypoint j-th keypoint.

Reimplemented in cv::xfeatures2d::DAISY.

defaultNorm()

virtual int cv::Feature2D::defaultNorm ( ) const

virtual

Python:
	retval	=	cv.Feature2D.defaultNorm(		)

descriptorSize()

virtual int cv::Feature2D::descriptorSize ( ) const

virtual

Python:
	retval	=	cv.Feature2D.descriptorSize(		)

descriptorType()

virtual int cv::Feature2D::descriptorType ( ) const

virtual

Python:
	retval	=	cv.Feature2D.descriptorType(		)

detect() [1/2]

virtual void cv::Feature2D::detect ( InputArray  image, std::vector< KeyPoint > &  keypoints, InputArray  mask = noArray()  )

virtual

Python:
	keypoints	=	cv.Feature2D.detect(	image[, mask]	)
	keypoints	=	cv.Feature2D.detect(	images[, masks]	)

Detects keypoints in an image (first variant) or image set (second variant).

Parameters

image	Image.
keypoints	The detected keypoints. In the second variant of the method keypoints[i] is a set of keypoints detected in images[i] .
mask	Mask specifying where to look for keypoints (optional). It must be a 8-bit integer matrix with non-zero values in the region of interest.

detect() [2/2]

virtual void cv::Feature2D::detect ( InputArrayOfArrays  images, std::vector< std::vector< KeyPoint > > &  keypoints, InputArrayOfArrays  masks = noArray()  )

virtual

Python:
	keypoints	=	cv.Feature2D.detect(	image[, mask]	)
	keypoints	=	cv.Feature2D.detect(	images[, masks]	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

images	Image set.
keypoints	The detected keypoints. In the second variant of the method keypoints[i] is a set of keypoints detected in images[i] .
masks	Masks for each input image specifying where to look for keypoints (optional). masks[i] is a mask for images[i].

detectAndCompute()

virtual void cv::Feature2D::detectAndCompute ( InputArray  image, InputArray  mask, std::vector< KeyPoint > &  keypoints, OutputArray  descriptors, bool  useProvidedKeypoints = false  )

virtual

Python:
	keypoints, descriptors	=	cv.Feature2D.detectAndCompute(	image, mask[, descriptors[, useProvidedKeypoints]]	)

Detects keypoints and computes the descriptors

empty()

virtual bool cv::Feature2D::empty ( ) const

virtual

Python:
	retval	=	cv.Feature2D.empty(		)

Return true if detector object is empty.

Reimplemented from cv::Algorithm.

getDefaultName()

virtual String cv::Feature2D::getDefaultName ( ) const

virtual

Python:
	retval	=	cv.Feature2D.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.

Reimplemented from cv::Algorithm.

Reimplemented in cv::AKAZE, cv::KAZE, cv::SimpleBlobDetector, cv::GFTTDetector, cv::AgastFeatureDetector, cv::FastFeatureDetector, cv::MSER, cv::ORB, cv::BRISK, cv::SIFT, and cv::AffineFeature.

read() [1/2]

void cv::Feature2D::read

(

const String &

fileName

)

Python:
	None	=	cv.Feature2D.read(	fileName	)
	None	=	cv.Feature2D.read(	arg1	)

read() [2/2]

virtual void cv::Feature2D::read ( const FileNode &  fn )

virtual

Python:
	None	=	cv.Feature2D.read(	fileName	)
	None	=	cv.Feature2D.read(	arg1	)

Reads algorithm parameters from a file storage.

Reimplemented from cv::Algorithm.

write() [1/3]

void cv::Feature2D::write

(

const String &

fileName

)

const

Python:
	None	=	cv.Feature2D.write(	fileName	)
	None	=	cv.Feature2D.write(	fs[, name]	)

write() [2/3]

virtual void cv::Feature2D::write ( FileStorage &  fs ) const

virtual

Python:
	None	=	cv.Feature2D.write(	fileName	)
	None	=	cv.Feature2D.write(	fs[, name]	)

Stores algorithm parameters in a file storage.

Reimplemented from cv::Algorithm.

write() [3/3]

void cv::Feature2D::write ( const Ptr< FileStorage > &  fs, const String &  name = String()  ) const

inline

Python:
	None	=	cv.Feature2D.write(	fileName	)
	None	=	cv.Feature2D.write(	fs[, name]	)

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

• opencv2/features2d.hpp