org.openimaj.image.feature.local.descriptor.gradient

Class IrregularBinningSIFTFeatureProvider

java.lang.Object

org.openimaj.image.feature.local.descriptor.gradient.IrregularBinningSIFTFeatureProvider

All Implemented Interfaces:

FeatureVectorProvider<OrientedFeatureVector>, GradientFeatureProvider, GradientFeatureProviderFactory, LocalFeatureProvider<OrientedFeatureVector>

@Reference(type=Inproceedings,
           author={"Cui, Yan","Hasler, Nils","Thorm\"{a}hlen, Thorsten","Seidel, Hans-Peter"},
           title="Scale Invariant Feature Transform with Irregular Orientation Histogram Binning",
           year="2009",
           booktitle="Proceedings of the 6th International Conference on Image Analysis and Recognition",
           pages={"258","","267"},
           publisher="Springer-Verlag",
           series="ICIAR \'09",
           customData={"Address","Berlin, Heidelberg"})
public class IrregularBinningSIFTFeatureProvider
extends Object
implements GradientFeatureProvider, GradientFeatureProviderFactory

Irregular binning SIFT descriptor based on this paper: CuiHasThoSei09igSIFT.pdf

Author:

Jonathon Hare (jsh2@ecs.soton.ac.uk)

Field Summary

Fields

Modifier and Type	Field and Description
protected int	numOriBins Number of orientation bins in the histograms
protected float	patchOrientation
protected float	valueThreshold Threshold for the maximum allowed value in the histogram
protected float[]	vec

Constructor Summary

Constructors

Constructor and Description
IrregularBinningSIFTFeatureProvider() Construct a IrregularBinningSIFTFeatureExtractor with the default parameters.
IrregularBinningSIFTFeatureProvider(int numOriBins) Construct a IrregularBinningSIFTFeatureExtractor with the default parameters.
IrregularBinningSIFTFeatureProvider(int numOriBins, float valueThreshold) Construct a IrregularBinningSIFTFeatureExtractor with the default parameters.

Method Summary

Modifier and Type	Method and Description
void	addSample(float x, float y, float gradmag, float gradori) Add a sample to the feature.
protected void	assignOri(int r, int c, float orif, float mag)
OrientedFeatureVector	getFeatureVector() Get the FeatureVector associated with this object.
float	getOversamplingAmount() Get the amount of required over-sampling outside of the unit square patch.
GradientFeatureProvider	newProvider() Construct a new GradientFeatureProvider implementation with all its internal settings setup ready for use.
void	setPatchOrientation(float patchOrientation) Set the primary orientation of the sample patch in the image being processed.

Methods inherited from class java.lang.Object

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

Field Detail

numOriBins

protected int numOriBins

Number of orientation bins in the histograms

valueThreshold

protected float valueThreshold

Threshold for the maximum allowed value in the histogram

patchOrientation

protected float patchOrientation

vec

protected float[] vec

Constructor Detail

IrregularBinningSIFTFeatureProvider

public IrregularBinningSIFTFeatureProvider()

Construct a IrregularBinningSIFTFeatureExtractor with the default parameters.

IrregularBinningSIFTFeatureProvider

public IrregularBinningSIFTFeatureProvider(int numOriBins)

Construct a IrregularBinningSIFTFeatureExtractor with the default parameters.

Parameters:

numOriBins - the number of orientation bins (default 8)

IrregularBinningSIFTFeatureProvider

public IrregularBinningSIFTFeatureProvider(int numOriBins,
                                           float valueThreshold)

Construct a IrregularBinningSIFTFeatureExtractor with the default parameters.

Parameters:

numOriBins - the number of orientation bins (default 8)

valueThreshold - threshold for the maximum value allowed in the histogram (default 0.2)

Method Detail

addSample

public void addSample(float x,
                      float y,
                      float gradmag,
                      float gradori)

Description copied from interface: GradientFeatureProvider

Add a sample to the feature. The x and y coordinates are given in terms of a unit index square (i.e. 0<=x<=1 and 0<=y<=1).

Specified by:

addSample in interface GradientFeatureProvider

Parameters:

x - x-coordinate within the unit indexing square

y - y-coordinate within the unit indexing square

gradmag - the gradient magnitude at the given coordinate

gradori - the gradient direction at the given coordinate

assignOri

protected void assignOri(int r,
                         int c,
                         float orif,
                         float mag)

getFeatureVector

public OrientedFeatureVector getFeatureVector()

Description copied from interface: FeatureVectorProvider

Get the FeatureVector associated with this object.

Specified by:

getFeatureVector in interface FeatureVectorProvider<OrientedFeatureVector>

Specified by:

getFeatureVector in interface GradientFeatureProvider

Returns:

the feature vector.

setPatchOrientation

public void setPatchOrientation(float patchOrientation)

Description copied from interface: GradientFeatureProvider

Set the primary orientation of the sample patch in the image being processed. This might be used by concrete implementations to provide rotation invariance. This method should only be called once by calling code, and the call should be before any calls to GradientFeatureProvider.addSample(float, float, float, float) are made.

Specified by:

setPatchOrientation in interface GradientFeatureProvider

Parameters:

patchOrientation - the actual orientation of the square in the image

newProvider

public GradientFeatureProvider newProvider()

Description copied from interface: GradientFeatureProviderFactory

Construct a new GradientFeatureProvider implementation with all its internal settings setup ready for use.

Specified by:

newProvider in interface GradientFeatureProviderFactory

Returns:

a new GradientFeatureProvider implementation.

getOversamplingAmount

public float getOversamplingAmount()

Description copied from interface: LocalFeatureProvider

Get the amount of required over-sampling outside of the unit square patch. An oversampling of 0.5 would result in methods such as SIFTFeatureProvider.addSample(float, float, float, float) being called with pixels in the range -0.5 to 1.5.

Specified by:

getOversamplingAmount in interface LocalFeatureProvider<OrientedFeatureVector>

Returns:

the amount over sampling above the unit square