public class InterestPointGradientFeatureExtractor extends Object implements FeatureVectorExtractor<OrientedFeatureVector,InterestPointImageExtractorProperties<Float,FImage>>
Class capable of extracting local descriptors from an interest point InterestPointData from an interest point detector InterestPointDetector.
The actual feature extracted is determined by the GradientFeatureProvider that
is provided by the GradientFeatureProviderFactory set during
construction.
The GradientFeatureExtractor first calculates the dominant orientation
of the image patch described by the InterestPointImageExtractorProperties
and then iterates over the pixels in an oriented square, centered on the
interest point, passing the gradient and magnitude values of the respective
pixel to the GradientFeatureProvider.
The size of the sampling square is exactly equal to the patch in the properties, this is in turn controlled by the interest point's scale and possibly its shape. For some types of feature provider, this number might need to be set based on the internal settings of the provider.
| Constructor and Description |
|---|
InterestPointGradientFeatureExtractor(AbstractDominantOrientationExtractor dominantOrientationExtractor,
GradientFeatureProviderFactory factory) |
| Modifier and Type | Method and Description |
|---|---|
protected OrientedFeatureVector |
createFeature(InterestPointImageExtractorProperties<Float,FImage> properties,
float orientation) |
OrientedFeatureVector[] |
extractFeature(InterestPointImageExtractorProperties<Float,FImage> properties)
Extract FeatureVector(s), possibly using the information given in the
properties.
|
GradientScaleSpaceImageExtractorProperties<FImage> |
getCurrentGradientProps(ScaleSpaceImageExtractorProperties<FImage> properties)
Get the GradientScaleSpaceImageExtractorProperties for the given properties.
|
public InterestPointGradientFeatureExtractor(AbstractDominantOrientationExtractor dominantOrientationExtractor, GradientFeatureProviderFactory factory)
dominantOrientationExtractor - how dominant orientations are locatedfactory - object used to construct GradientFeatureProvider instances which in turn
construction the actual featurespublic GradientScaleSpaceImageExtractorProperties<FImage> getCurrentGradientProps(ScaleSpaceImageExtractorProperties<FImage> properties)
properties - input propertiespublic OrientedFeatureVector[] extractFeature(InterestPointImageExtractorProperties<Float,FImage> properties)
FeatureVectorExtractorextractFeature in interface FeatureVectorExtractor<OrientedFeatureVector,InterestPointImageExtractorProperties<Float,FImage>>properties - Properties describing how the features should be extracted.protected OrientedFeatureVector createFeature(InterestPointImageExtractorProperties<Float,FImage> properties, float orientation)