OpenCV  3.2.0-dev
Open Source Computer Vision
cv::AKAZE Class Referenceabstract

Class implementing the AKAZE keypoint detector and descriptor extractor, described in [1] . More...

#include "features2d.hpp"

Inheritance diagram for cv::AKAZE:
Collaboration diagram for cv::AKAZE:

Public Types

enum  {
  DESCRIPTOR_KAZE_UPRIGHT = 2,
  DESCRIPTOR_KAZE = 3,
  DESCRIPTOR_MLDB_UPRIGHT = 4,
  DESCRIPTOR_MLDB = 5
}
 

Public Member Functions

virtual void clear ()
 Clears the algorithm state. More...
 
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)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...
 
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())
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...
 
virtual void detectAndCompute (InputArray image, InputArray mask, std::vector< KeyPoint > &keypoints, OutputArray descriptors, bool useProvidedKeypoints=false)
 Detects keypoints and computes the descriptors. More...
 
virtual bool empty () const
 Return true if detector object is empty. More...
 
virtual String getDefaultName () const
 Returns the algorithm string identifier. More...
 
virtual int getDescriptorChannels () const =0
 
virtual int getDescriptorSize () const =0
 
virtual int getDescriptorType () const =0
 
virtual int getDiffusivity () const =0
 
virtual int getNOctaveLayers () const =0
 
virtual int getNOctaves () const =0
 
virtual double getThreshold () const =0
 
void read (const String &fileName)
 
virtual void read (const FileNode &)
 Reads algorithm parameters from a file storage. More...
 
virtual void save (const String &filename) const
 Saves the algorithm to a file. More...
 
virtual void setDescriptorChannels (int dch)=0
 
virtual void setDescriptorSize (int dsize)=0
 
virtual void setDescriptorType (int dtype)=0
 
virtual void setDiffusivity (int diff)=0
 
virtual void setNOctaveLayers (int octaveLayers)=0
 
virtual void setNOctaves (int octaves)=0
 
virtual void setThreshold (double threshold)=0
 
void write (const String &fileName) const
 
virtual void write (FileStorage &) const
 Stores algorithm parameters in a file storage. More...
 

Static Public Member Functions

static Ptr< AKAZEcreate (int descriptor_type=AKAZE::DESCRIPTOR_MLDB, int descriptor_size=0, int descriptor_channels=3, float threshold=0.001f, int nOctaves=4, int nOctaveLayers=4, int diffusivity=KAZE::DIFF_PM_G2)
 The AKAZE constructor. More...
 
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...
 

Protected Member Functions

void writeFormat (FileStorage &fs) const
 

Detailed Description

Class implementing the AKAZE keypoint detector and descriptor extractor, described in [1] .

:

Note
AKAZE descriptors can only be used with KAZE or AKAZE keypoints. Try to avoid using extract and detect instead of operator() due to performance reasons. .. [ANB13] Fast Explicit Diffusion for Accelerated Features in Nonlinear Scale Spaces. Pablo F. Alcantarilla, Jesús Nuevo and Adrien Bartoli. In British Machine Vision Conference (BMVC), Bristol, UK, September 2013.

Member Enumeration Documentation

anonymous enum
Enumerator
DESCRIPTOR_KAZE_UPRIGHT 

Upright descriptors, not invariant to rotation.

DESCRIPTOR_KAZE 
DESCRIPTOR_MLDB_UPRIGHT 

Upright descriptors, not invariant to rotation.

DESCRIPTOR_MLDB 

Member Function Documentation

virtual void cv::Algorithm::clear ( )
inlinevirtualinherited

Clears the algorithm state.

Reimplemented in cv::FlannBasedMatcher, cv::DescriptorMatcher, and cv::cuda::DescriptorMatcher.

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

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

Parameters
imageImage.
keypointsInput 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).
descriptorsComputed 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.
virtual void cv::Feature2D::compute ( InputArrayOfArrays  images,
std::vector< std::vector< KeyPoint > > &  keypoints,
OutputArrayOfArrays  descriptors 
)
virtualinherited

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

Parameters
imagesImage set.
keypointsInput 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).
descriptorsComputed 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.
static Ptr<AKAZE> cv::AKAZE::create ( int  descriptor_type = AKAZE::DESCRIPTOR_MLDB,
int  descriptor_size = 0,
int  descriptor_channels = 3,
float  threshold = 0.001f,
int  nOctaves = 4,
int  nOctaveLayers = 4,
int  diffusivity = KAZE::DIFF_PM_G2 
)
static

The AKAZE constructor.

Parameters
descriptor_typeType of the extracted descriptor: DESCRIPTOR_KAZE, DESCRIPTOR_KAZE_UPRIGHT, DESCRIPTOR_MLDB or DESCRIPTOR_MLDB_UPRIGHT.
descriptor_sizeSize of the descriptor in bits. 0 -> Full size
descriptor_channelsNumber of channels in the descriptor (1, 2, 3)
thresholdDetector response threshold to accept point
nOctavesMaximum octave evolution of the image
nOctaveLayersDefault number of sublevels per scale level
diffusivityDiffusivity type. DIFF_PM_G1, DIFF_PM_G2, DIFF_WEICKERT or DIFF_CHARBONNIER
virtual int cv::Feature2D::defaultNorm ( ) const
virtualinherited
virtual int cv::Feature2D::descriptorSize ( ) const
virtualinherited
virtual int cv::Feature2D::descriptorType ( ) const
virtualinherited
virtual void cv::Feature2D::detect ( InputArray  image,
std::vector< KeyPoint > &  keypoints,
InputArray  mask = noArray() 
)
virtualinherited

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

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

Reimplemented in cv::AgastFeatureDetector_Impl.

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

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

Parameters
imagesImage set.
keypointsThe detected keypoints. In the second variant of the method keypoints[i] is a set of keypoints detected in images[i] .
masksMasks for each input image specifying where to look for keypoints (optional). masks[i] is a mask for images[i].
virtual void cv::Feature2D::detectAndCompute ( InputArray  image,
InputArray  mask,
std::vector< KeyPoint > &  keypoints,
OutputArray  descriptors,
bool  useProvidedKeypoints = false 
)
virtualinherited

Detects keypoints and computes the descriptors.

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

Return true if detector object is empty.

Reimplemented from cv::Algorithm.

virtual String cv::Algorithm::getDefaultName ( ) const
virtualinherited

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.

virtual int cv::AKAZE::getDescriptorChannels ( ) const
pure virtual
virtual int cv::AKAZE::getDescriptorSize ( ) const
pure virtual
virtual int cv::AKAZE::getDescriptorType ( ) const
pure virtual
virtual int cv::AKAZE::getDiffusivity ( ) const
pure virtual
virtual int cv::AKAZE::getNOctaveLayers ( ) const
pure virtual
virtual int cv::AKAZE::getNOctaves ( ) const
pure virtual
virtual double cv::AKAZE::getThreshold ( ) const
pure virtual
template<typename _Tp >
static Ptr<_Tp> cv::Algorithm::load ( const String filename,
const String objname = String() 
)
inlinestaticinherited

Loads algorithm from the file.

Parameters
filenameName of the file to read.
objnameThe optional name of the node to read (if empty, the first top-level node will be used)

This is static template method of Algorithm. It's usage is following (in the case of SVM):

Ptr<SVM> svm = Algorithm::load<SVM>("my_svm_model.xml");

In order to make this method work, the derived class must overwrite Algorithm::read(const FileNode& fn).

References cv::Ptr< T >::empty(), cv::FileNode::empty(), cv::FileStorage::getFirstTopLevelNode(), and cv::FileStorage::READ.

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template<typename _Tp >
static Ptr<_Tp> cv::Algorithm::loadFromString ( const String strModel,
const String objname = String() 
)
inlinestaticinherited

Loads algorithm from a String.

Parameters
strModelThe string variable containing the model you want to load.
objnameThe optional name of the node to read (if empty, the first top-level node will be used)

This is static template method of Algorithm. It's usage is following (in the case of SVM):

Ptr<SVM> svm = Algorithm::loadFromString<SVM>(myStringModel);

References CV_WRAP, cv::Ptr< T >::empty(), cv::FileNode::empty(), cv::FileStorage::getFirstTopLevelNode(), cv::FileStorage::MEMORY, and cv::FileStorage::READ.

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void cv::Feature2D::read ( const String fileName)
inherited
virtual void cv::Feature2D::read ( const FileNode fn)
virtualinherited

Reads algorithm parameters from a file storage.

Reimplemented from cv::Algorithm.

virtual void cv::Algorithm::save ( const String filename) const
virtualinherited

Saves the algorithm to a file.

In order to make this method work, the derived class must implement Algorithm::write(FileStorage& fs).

virtual void cv::AKAZE::setDescriptorChannels ( int  dch)
pure virtual
virtual void cv::AKAZE::setDescriptorSize ( int  dsize)
pure virtual
virtual void cv::AKAZE::setDescriptorType ( int  dtype)
pure virtual
virtual void cv::AKAZE::setDiffusivity ( int  diff)
pure virtual
virtual void cv::AKAZE::setNOctaveLayers ( int  octaveLayers)
pure virtual
virtual void cv::AKAZE::setNOctaves ( int  octaves)
pure virtual
virtual void cv::AKAZE::setThreshold ( double  threshold)
pure virtual
void cv::Feature2D::write ( const String fileName) const
inherited
virtual void cv::Feature2D::write ( FileStorage fs) const
virtualinherited

Stores algorithm parameters in a file storage.

Reimplemented from cv::Algorithm.

void cv::Algorithm::writeFormat ( FileStorage fs) const
protectedinherited

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