org.bytedeco.javacpp

Class opencv_features2d.KeyPoint

java.lang.Object

org.bytedeco.javacpp.Pointer

org.bytedeco.javacpp.opencv_features2d.KeyPoint

Enclosing class:

opencv_features2d

public static class opencv_features2d.KeyPoint
extends Pointer

The Keypoint Class The class instance stores a keypoint, i.e. a point feature found by one of many available keypoint detectors, such as Harris corner detector, cv::FAST, cv::StarDetector, cv::SURF, cv::SIFT, cv::LDetector etc. The keypoint is characterized by the 2D position, scale (proportional to the diameter of the neighborhood that needs to be taken into account), orientation and some other parameters. The keypoint neighborhood is then analyzed by another algorithm that builds a descriptor (usually represented as a feature vector). The keypoints representing the same object in different images can then be matched using cv::KDTree or another method.

Nested Class Summary

Nested classes/interfaces inherited from class org.bytedeco.javacpp.Pointer

Pointer.CustomDeallocator, Pointer.Deallocator, Pointer.NativeDeallocator

Field Summary

Fields inherited from class org.bytedeco.javacpp.Pointer

address, capacity, limit, position

Constructor Summary

Constructors

Constructor and Description
opencv_features2d.KeyPoint() the default constructor
opencv_features2d.KeyPoint(float x, float y, float _size)
opencv_features2d.KeyPoint(float x, float y, float _size, float _angle, float _response, int _octave, int _class_id) another form of the full constructor
opencv_features2d.KeyPoint(int size)
opencv_features2d.KeyPoint(opencv_core.Point2f _pt, float _size)
opencv_features2d.KeyPoint(opencv_core.Point2f _pt, float _size, float _angle, float _response, int _octave, int _class_id) the full constructor
opencv_features2d.KeyPoint(Pointer p)

Method Summary

Methods

Modifier and Type	Method and Description
float	angle() computed orientation of the keypoint (-1 if not applicable); * it's in [0,360) degrees and measured relative to * image coordinate system, ie in clockwise.
opencv_features2d.KeyPoint	angle(float angle)
int	class_id() object class (if the keypoints need to be clustered by an object they belong to)
opencv_features2d.KeyPoint	class_id(int class_id)
static void	convert(opencv_core.Point2f points2f, opencv_features2d.KeyPoint keypoints)
static void	convert(opencv_core.Point2f points2f, opencv_features2d.KeyPoint keypoints, float size, float response, int octave, int class_id) converts vector of points to the vector of keypoints, where each keypoint is assigned the same size and the same orientation
static void	convert(opencv_features2d.KeyPoint keypoints, opencv_core.Point2f points2f)
static void	convert(opencv_features2d.KeyPoint keypoints, opencv_core.Point2f points2f, int[] keypointIndexes)
static void	convert(opencv_features2d.KeyPoint keypoints, opencv_core.Point2f points2f, IntBuffer keypointIndexes)
static void	convert(opencv_features2d.KeyPoint keypoints, opencv_core.Point2f points2f, IntPointer keypointIndexes) converts vector of keypoints to vector of points
long	hash()
int	octave() octave (pyramid layer) from which the keypoint has been extracted
opencv_features2d.KeyPoint	octave(int octave)
static float	overlap(opencv_features2d.KeyPoint kp1, opencv_features2d.KeyPoint kp2) computes overlap for pair of keypoints; overlap is a ratio between area of keypoint regions intersection and area of keypoint regions union (now keypoint region is circle)
opencv_features2d.KeyPoint	position(int position)
opencv_core.Point2f	pt() coordinates of the keypoints
opencv_features2d.KeyPoint	pt(opencv_core.Point2f pt)
float	response() the response by which the most strong keypoints have been selected.
opencv_features2d.KeyPoint	response(float response)
float	size() diameter of the meaningful keypoint neighborhood
opencv_features2d.KeyPoint	size(float size)

Methods inherited from class org.bytedeco.javacpp.Pointer

address, asBuffer, asByteBuffer, capacity, capacity, deallocate, deallocate, deallocateReferences, deallocator, deallocator, equals, fill, hashCode, isNull, limit, limit, memchr, memcmp, memcpy, memmove, memset, offsetof, position, put, setNull, sizeof, toString, withDeallocator, zero

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

opencv_features2d.KeyPoint

public opencv_features2d.KeyPoint(Pointer p)

opencv_features2d.KeyPoint

public opencv_features2d.KeyPoint(int size)

opencv_features2d.KeyPoint

public opencv_features2d.KeyPoint()

the default constructor

opencv_features2d.KeyPoint

public opencv_features2d.KeyPoint(opencv_core.Point2f _pt,
                          float _size,
                          float _angle,
                          float _response,
                          int _octave,
                          int _class_id)

the full constructor

opencv_features2d.KeyPoint

public opencv_features2d.KeyPoint(opencv_core.Point2f _pt,
                          float _size)

opencv_features2d.KeyPoint

public opencv_features2d.KeyPoint(float x,
                          float y,
                          float _size,
                          float _angle,
                          float _response,
                          int _octave,
                          int _class_id)

another form of the full constructor

opencv_features2d.KeyPoint

public opencv_features2d.KeyPoint(float x,
                          float y,
                          float _size)

Method Detail

position

public opencv_features2d.KeyPoint position(int position)

Overrides:

position in class Pointer

hash

public long hash()

convert

public static void convert(opencv_features2d.KeyPoint keypoints,
           opencv_core.Point2f points2f,
           IntPointer keypointIndexes)

converts vector of keypoints to vector of points

convert

public static void convert(opencv_features2d.KeyPoint keypoints,
           opencv_core.Point2f points2f)

convert

public static void convert(opencv_features2d.KeyPoint keypoints,
           opencv_core.Point2f points2f,
           IntBuffer keypointIndexes)

convert

public static void convert(opencv_features2d.KeyPoint keypoints,
           opencv_core.Point2f points2f,
           int[] keypointIndexes)

convert

public static void convert(opencv_core.Point2f points2f,
           opencv_features2d.KeyPoint keypoints,
           float size,
           float response,
           int octave,
           int class_id)

converts vector of points to the vector of keypoints, where each keypoint is assigned the same size and the same orientation

convert

public static void convert(opencv_core.Point2f points2f,
           opencv_features2d.KeyPoint keypoints)

overlap

public static float overlap(opencv_features2d.KeyPoint kp1,
            opencv_features2d.KeyPoint kp2)

computes overlap for pair of keypoints; overlap is a ratio between area of keypoint regions intersection and area of keypoint regions union (now keypoint region is circle)

pt

public opencv_core.Point2f pt()

coordinates of the keypoints

pt

public opencv_features2d.KeyPoint pt(opencv_core.Point2f pt)

size

public float size()

diameter of the meaningful keypoint neighborhood

size

public opencv_features2d.KeyPoint size(float size)

angle

public float angle()

computed orientation of the keypoint (-1 if not applicable); * it's in [0,360) degrees and measured relative to * image coordinate system, ie in clockwise.

angle

public opencv_features2d.KeyPoint angle(float angle)

response

public float response()

the response by which the most strong keypoints have been selected. Can be used for the further sorting or subsampling

response

public opencv_features2d.KeyPoint response(float response)

octave

public int octave()

octave (pyramid layer) from which the keypoint has been extracted

octave

public opencv_features2d.KeyPoint octave(int octave)

class_id

public int class_id()

object class (if the keypoints need to be clustered by an object they belong to)

class_id

public opencv_features2d.KeyPoint class_id(int class_id)