boofcv.alg.feature.detect.interest

Class SiftScaleSpace

java.lang.Object

boofcv.alg.feature.detect.interest.SiftScaleSpace

public class SiftScaleSpace
extends java.lang.Object

Generates the pyramidal scale space as described in the SIFT [1] paper. This is, for the most part, is intended to be a faithful reproduction of the original work.

Known Deviations From Original SIFT:

• No prior blur is applied to input image. Nor should you apply any.

[1] Lowe, D. "Distinctive image features from scale-invariant keypoints". International Journal of Computer Vision, 60, 2 (2004), pp.91--110.

Constructor Summary

Constructors

Constructor and Description
SiftScaleSpace(int firstOctave, int lastOctave, int numScales, double sigma0) Configures the scale-space

Method Summary

Modifier and Type	Method and Description
boolean	computeNextOctave() Computes the next octave.
double	computeSigmaScale(int scale) Computes the effective amount of blur at the given scale in the current octave.
double	computeSigmaScale(int octave, int scale) Returns the blur at the given octave and scale
int	getCurrentOctave()
GrayF32	getDifferenceOfGaussian(int dogIndex)
GrayF32	getImageScale(int scaleIndex)
int	getNumScaleImages()
int	getNumScales()
int	getTotalOctaves()
void	initialize(GrayF32 input)
double	pixelScaleCurrentToInput() Returns the size of a pixel in the current octave relative to the size of a pixel in the input image

Methods inherited from class java.lang.Object

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

Constructor Detail

SiftScaleSpace

public SiftScaleSpace(int firstOctave,
                      int lastOctave,
                      int numScales,
                      double sigma0)

Configures the scale-space

Parameters:

firstOctave - Initial octave. Negative numbers means it will scale up. Recommend 0 or -1.

lastOctave - Last octave, inclusive. Recommend ????

numScales - Number of scales in each octave. Recommend 3.

sigma0 - Amount of blur at the first level in the image pyramid. Recommend 1.6

Method Detail

computeSigmaScale

public double computeSigmaScale(int scale)

Computes the effective amount of blur at the given scale in the current octave.

computeSigmaScale

public double computeSigmaScale(int octave,
                                int scale)

Returns the blur at the given octave and scale

initialize

public void initialize(GrayF32 input)

Parameters:

input - Input image. No prior blur should be applied to this image. Not modified.

computeNextOctave

public boolean computeNextOctave()

Computes the next octave. If the last octave has already been computed false is returned.

Returns:

true if an octave was computed or false if the last one was already reached

getImageScale

public GrayF32 getImageScale(int scaleIndex)

getDifferenceOfGaussian

public GrayF32 getDifferenceOfGaussian(int dogIndex)

getNumScales

public int getNumScales()

getNumScaleImages

public int getNumScaleImages()

getCurrentOctave

public int getCurrentOctave()

getTotalOctaves

public int getTotalOctaves()

pixelScaleCurrentToInput

public double pixelScaleCurrentToInput()

Returns the size of a pixel in the current octave relative to the size of a pixel in the input image

Returns:

pixel size to input image