See: Description
Interface  Description 

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

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.

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.
Copyright © 2024 Central Laboratory of the Research Councils. All Rights Reserved.