Package diva.sketch.features

This package implements feature extraction including Rubine's list of features given in [1].

See: Description

Interface Summary

Interface	Description
FeatureExtractor	A feature extractor performs computation on a stroke and outputs a value that represents the stroke's feature.

Class Summary

Class	Description
AreaRatioFE	AreaRatioFE calculates the ratio of the convex hull area and the bounding box area of a stroke, (convex_hull/bbox).
AspectRatioFE	AspectRatioFE calculates the ratio of the width and the height from a stroke's bounding box, (width/height).
BBoxDiagonalAngleFE	BBoxDiagonalAngleFE computes the angle between the diagonal and the base of a stroke's bounding box.
BBoxDiagonalLengthFE	BBoxDiagonalLengthFE computes the diagonal length of a stroke's bounding box.
ConvexHull	A ConvexHull object implements the Quickhull algorithm to find the planar convex hull of a set of points.
CornerFE	CornerFE computes the number of corners in a stroke by enumerating over the data points in the stroke.
CosFirstLastPtsFE
CosInitAngleFE	CosInitAngleFE computes the cosine of the initial angle of a stroke.
DistanceStartEndPtsFE	DistanceStartEndPtsFE computes the distance between the first and the last point of a stroke.
DurationFE	DurationFE computes the amount of time taken to draw a stroke.
FEUtilities	Common calculation methods used in path filtering and feature extraction processes.
MaxSpeedFE	MaxSpeedFE computes the maximum speed (squared) along the path of a stroke.
PathLengthFE	PathLengthFE computes the path length of a stroke by enumerating over the points in the stroke and summing up the distances between every two consecutive points.
PathRatioFE	PathRatioFE computes the ratio between a stroke's convex hull path length and its actual path length, (convex_hull/pathlen).
SineFirstLastPtsFE	SineFirstLastPtsFE computes the sine of the angle between the first and the last points of a stroke.
SineInitAngleFE	SineInitAngleFE computes the sine of the initial angle of a stroke.
StrokeBBox	StrokeBBox computes the bounding box of a stroke and stores the result in the stroke's property table.
StrokeHull	StrokeHull computes the convex hull of a stroke and stores the result in the stroke's property table.
SumOfAbsDeltaRatioFE	SumOfAbsDeltaRatioFE computes the ratio of the sum of the absolute values of the delta y's and the sum of the absolute values of the delta x's (sum of |delta y|)/(sum of |delta x|).
SumOfAbsoluteAnglesFE	SumOfAbsoluteAnglesFE computes the sum of the absolute values of the angles along a stroke path.
SumOfAnglesFE	SumOfAnglesFE computes the total angle traversed by a stroke.
SumOfSquaredAnglesFE	SumOfSquaredAnglesFE computes the sum of squared angle values along a stroke path.

Package diva.sketch.features Description

This package implements feature extraction including Rubine's list of features given in [1]. Feature extraction means calculating a particular scalar characteristic (e.g. aspect ratio) of a stroke. AreaRatioFE, CornerFE, and SumOfAbsDeltaRatioFE are features that we added on top of Rubine's features.

[1] "Specifying Gestures by Example", Dean Rubine, Computer Graphics, Volume25, Number4, July 1991.