boofcv.alg.feature.detect.interest

Class SiftDetector

java.lang.Object

boofcv.alg.feature.detect.interest.SiftDetector

public class SiftDetector
extends java.lang.Object

Feature detector described in the Scale Invariant Feature Transform (SIFT) paper [1]. Location and scale of blob like features are detected using a Difference of Gaussian (DOG) across scale-space. Note the algorithmic changes below.

INTERPOLATION: Location and scale interpolation is done using a second order polynomial. This avoids taking the second order derivative numerically, which is very sensitive to noise. Plus I disagree with his statement that peaks outside the local region are valid and require iteration.

LOW CONTRAST REJECTION: Try adjusting detection radius to reduce the number of low contrast returns instead. The technique proposed in the paper was not tested.

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

Field Summary

Fields

Modifier and Type	Field and Description
protected SiftImageScaleSpace	ss

Constructor Summary

Constructors

Constructor and Description
SiftDetector(NonMaxSuppression extractor, int maxFeaturesPerScale, double edgeThreshold) Configures SIFT

Method Summary

Methods

Modifier and Type	Method and Description
org.ddogleg.struct.FastQueue<ScalePoint>	getFoundPoints() Returns all the found points
void	process(SiftImageScaleSpace ss)

Methods inherited from class java.lang.Object

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

Field Detail

ss

protected SiftImageScaleSpace ss

Constructor Detail

SiftDetector

public SiftDetector(NonMaxSuppression extractor,
            int maxFeaturesPerScale,
            double edgeThreshold)

Configures SIFT

Parameters:

extractor - Extracts local maximums from each scale.

maxFeaturesPerScale - Max detected features per scale. Disable with < 0. Try 500

edgeThreshold - Threshold for edge filtering. Disable with a value <= 0. Try 5

Method Detail

process

public void process(SiftImageScaleSpace ss)

getFoundPoints

public org.ddogleg.struct.FastQueue<ScalePoint> getFoundPoints()

Returns all the found points