org.opencv.features2d

Class Feature2D

java.lang.Object

org.opencv.core.Algorithm

org.opencv.features2d.Feature2D

Direct Known Subclasses:

AffineFeature, AgastFeatureDetector, AKAZE, BRISK, FastFeatureDetector, GFTTDetector, KAZE, MSER, ORB, SIFT, SimpleBlobDetector

public class Feature2D
extends Algorithm

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

Method Summary

Modifier and Type	Method and Description
static Feature2D	__fromPtr__(long addr)
void	compute(java.util.List<Mat> images, java.util.List<MatOfKeyPoint> keypoints, java.util.List<Mat> descriptors)
void	compute(Mat image, MatOfKeyPoint keypoints, Mat descriptors) Computes the descriptors for a set of keypoints detected in an image (first variant) or image set (second variant).
int	defaultNorm()
int	descriptorSize()
int	descriptorType()
void	detect(java.util.List<Mat> images, java.util.List<MatOfKeyPoint> keypoints)
void	detect(java.util.List<Mat> images, java.util.List<MatOfKeyPoint> keypoints, java.util.List<Mat> masks)
void	detect(Mat image, MatOfKeyPoint keypoints) Detects keypoints in an image (first variant) or image set (second variant).
void	detect(Mat image, MatOfKeyPoint keypoints, Mat mask) Detects keypoints in an image (first variant) or image set (second variant).
void	detectAndCompute(Mat image, Mat mask, MatOfKeyPoint keypoints, Mat descriptors) Detects keypoints and computes the descriptors
void	detectAndCompute(Mat image, Mat mask, MatOfKeyPoint keypoints, Mat descriptors, boolean useProvidedKeypoints) Detects keypoints and computes the descriptors
boolean	empty() Returns true if the Algorithm is empty (e.g.
java.lang.String	getDefaultName() Returns the algorithm string identifier.
void	read(java.lang.String fileName)
void	write(java.lang.String fileName)

Methods inherited from class org.opencv.core.Algorithm

clear, getNativeObjAddr, save

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

__fromPtr__

public static Feature2D __fromPtr__(long addr)

compute

public void compute(java.util.List<Mat> images,
                    java.util.List<MatOfKeyPoint> keypoints,
                    java.util.List<Mat> descriptors)

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.

compute

public void compute(Mat image,
                    MatOfKeyPoint keypoints,
                    Mat 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.

defaultNorm

public int defaultNorm()

descriptorSize

public int descriptorSize()

descriptorType

public int descriptorType()

detect

public void detect(java.util.List<Mat> images,
                   java.util.List<MatOfKeyPoint> keypoints)

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[i] is a mask for images[i].

detect

public void detect(java.util.List<Mat> images,
                   java.util.List<MatOfKeyPoint> keypoints,
                   java.util.List<Mat> masks)

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].

detect

public void detect(Mat image,
                   MatOfKeyPoint keypoints)

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] . matrix with non-zero values in the region of interest.

detect

public void detect(Mat image,
                   MatOfKeyPoint keypoints,
                   Mat mask)

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.

detectAndCompute

public void detectAndCompute(Mat image,
                             Mat mask,
                             MatOfKeyPoint keypoints,
                             Mat descriptors)

Detects keypoints and computes the descriptors

Parameters:

image - automatically generated

mask - automatically generated

keypoints - automatically generated

descriptors - automatically generated

detectAndCompute

public void detectAndCompute(Mat image,
                             Mat mask,
                             MatOfKeyPoint keypoints,
                             Mat descriptors,
                             boolean useProvidedKeypoints)

Detects keypoints and computes the descriptors

Parameters:

image - automatically generated

mask - automatically generated

keypoints - automatically generated

descriptors - automatically generated

useProvidedKeypoints - automatically generated

empty

public boolean empty()

Description copied from class: Algorithm

Returns true if the Algorithm is empty (e.g. in the very beginning or after unsuccessful read

Overrides:

empty in class Algorithm

Returns:

automatically generated

getDefaultName

public java.lang.String getDefaultName()

Description copied from class: Algorithm

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.

Overrides:

getDefaultName in class Algorithm

Returns:

automatically generated

read

public void read(java.lang.String fileName)

write

public void write(java.lang.String fileName)