org.bytedeco.opencv.opencv_features2d

Class SIFT

java.lang.Object

org.bytedeco.javacpp.Pointer

org.bytedeco.opencv.opencv_core.Algorithm

org.bytedeco.opencv.opencv_features2d.Feature2D

org.bytedeco.opencv.opencv_features2d.SIFT

All Implemented Interfaces:

AutoCloseable

@Namespace(value="cv")
 @Properties(inherit=opencv_features2d.class)
public class SIFT
extends Feature2D

\brief Class for extracting keypoints and computing descriptors using the Scale Invariant Feature Transform (SIFT) algorithm by D. Lowe \cite Lowe04 .

Nested Class Summary

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

Pointer.CustomDeallocator, Pointer.Deallocator, Pointer.NativeDeallocator, Pointer.ReferenceCounter

Field Summary

Fields inherited from class org.bytedeco.javacpp.Pointer

address, capacity, limit, position

Constructor Summary

Constructors

Constructor and Description
SIFT() Default native constructor.
SIFT(long size) Native array allocator.
SIFT(Pointer p) Pointer cast constructor.

Method Summary

Modifier and Type	Method and Description
static SIFT	create()
static SIFT	create(int nfeatures, int nOctaveLayers, double contrastThreshold, double edgeThreshold, double sigma)
static SIFT	create(int nfeatures, int nOctaveLayers, double contrastThreshold, double edgeThreshold, double sigma, int descriptorType) \brief Create SIFT with specified descriptorType.
BytePointer	getDefaultName() Returns the algorithm string identifier.
SIFT	getPointer(long i)
SIFT	position(long position)

Methods inherited from class org.bytedeco.opencv.opencv_features2d.Feature2D

compute, compute, compute, compute, compute, compute, defaultNorm, descriptorSize, descriptorType, detect, detect, detect, detect, detect, detect, detect, detect, detect, detect, detect, detect, detectAndCompute, detectAndCompute, detectAndCompute, detectAndCompute, detectAndCompute, detectAndCompute, empty, read, read, read, write, write, write, write, write

Methods inherited from class org.bytedeco.opencv.opencv_core.Algorithm

clear, save, save

Methods inherited from class org.bytedeco.javacpp.Pointer

address, asBuffer, asByteBuffer, availablePhysicalBytes, calloc, capacity, capacity, close, deallocate, deallocate, deallocateReferences, deallocator, deallocator, equals, fill, formatBytes, free, getPointer, getPointer, getPointer, hashCode, interruptDeallocatorThread, isNull, isNull, limit, limit, malloc, maxBytes, maxPhysicalBytes, memchr, memcmp, memcpy, memmove, memset, offsetAddress, offsetof, offsetof, parseBytes, physicalBytes, physicalBytesInaccurate, position, put, realloc, referenceCount, releaseReference, retainReference, setNull, sizeof, sizeof, toString, totalBytes, totalCount, totalPhysicalBytes, withDeallocator, zero

Methods inherited from class java.lang.Object

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

Constructor Detail

SIFT

public SIFT()

Default native constructor.

SIFT

public SIFT(long size)

Native array allocator. Access with Pointer.position(long).

SIFT

public SIFT(Pointer p)

Pointer cast constructor. Invokes Pointer(Pointer).

Method Detail

position

public SIFT position(long position)

Overrides:

position in class Feature2D

getPointer

public SIFT getPointer(long i)

Overrides:

getPointer in class Feature2D

create

@opencv_core.Ptr
public static SIFT create(int nfeatures,
                                           int nOctaveLayers,
                                           double contrastThreshold,
                                           double edgeThreshold,
                                           double sigma)

Parameters:

nfeatures - The number of best features to retain. The features are ranked by their scores (measured in SIFT algorithm as the local contrast)

nOctaveLayers - The number of layers in each octave. 3 is the value used in D. Lowe paper. The number of octaves is computed automatically from the image resolution.

contrastThreshold - The contrast threshold used to filter out weak features in semi-uniform (low-contrast) regions. The larger the threshold, the less features are produced by the detector.

\note The contrast threshold will be divided by nOctaveLayers when the filtering is applied. When nOctaveLayers is set to default and if you want to use the value used in D. Lowe paper, 0.03, set this argument to 0.09.

edgeThreshold - The threshold used to filter out edge-like features. Note that the its meaning is different from the contrastThreshold, i.e. the larger the edgeThreshold, the less features are filtered out (more features are retained).

sigma - The sigma of the Gaussian applied to the input image at the octave \#0. If your image is captured with a weak camera with soft lenses, you might want to reduce the number.

create

@opencv_core.Ptr
public static SIFT create()

create

@opencv_core.Ptr
public static SIFT create(int nfeatures,
                                           int nOctaveLayers,
                                           double contrastThreshold,
                                           double edgeThreshold,
                                           double sigma,
                                           int descriptorType)

\brief Create SIFT with specified descriptorType.

Parameters:

nfeatures - The number of best features to retain. The features are ranked by their scores (measured in SIFT algorithm as the local contrast)

nOctaveLayers - The number of layers in each octave. 3 is the value used in D. Lowe paper. The number of octaves is computed automatically from the image resolution.

contrastThreshold - The contrast threshold used to filter out weak features in semi-uniform (low-contrast) regions. The larger the threshold, the less features are produced by the detector.

\note The contrast threshold will be divided by nOctaveLayers when the filtering is applied. When nOctaveLayers is set to default and if you want to use the value used in D. Lowe paper, 0.03, set this argument to 0.09.

edgeThreshold - The threshold used to filter out edge-like features. Note that the its meaning is different from the contrastThreshold, i.e. the larger the edgeThreshold, the less features are filtered out (more features are retained).

sigma - The sigma of the Gaussian applied to the input image at the octave \#0. If your image is captured with a weak camera with soft lenses, you might want to reduce the number.

descriptorType - The type of descriptors. Only CV_32F and CV_8U are supported.

getDefaultName

@opencv_core.Str
public BytePointer 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 Feature2D