diva.sketch.toolbox

Class DehookingStrokeFilter

java.lang.Object

diva.sketch.toolbox.StrokeFilter

diva.sketch.toolbox.DehookingStrokeFilter

public class DehookingStrokeFilter
extends StrokeFilter

Eliminate the serifs at the ends of a stroke. (W.W.Loy and I.D.Landau, "An On-Line Procedure for Recognition of Handprinted Alphanumeric Characters", IEEE transactions on PAMI, Vol. PAMI-4, No.4, July 1982)

Version:

$Revision: 1.7 $

Author:

Heloise Hse (hwawen@eecs.berkeley.edu)

Field Summary

Fields

Modifier and Type	Field and Description
static double	DEFAULT_ANGLE_THRESHOLD

Fields inherited from class diva.sketch.toolbox.StrokeFilter

PROPERTY_KEY

Constructor Summary

Constructors

Constructor and Description
DehookingStrokeFilter() Create a dehooking stroke filter with the default parameters.

Method Summary

Modifier and Type	Method and Description
TimedStroke	apply(TimedStroke s) Apply a filtering algorithm on the specified pen stroke and return the filtered stroke.
static TimedStroke	dehook(TimedStroke s) At the beginning and the end of the given stroke, calculate the general direction vectors by taking the 2/10 of the total length from each end.
static TimedStroke	dehook(TimedStroke s, double angleThresh)
static TimedStroke	dehook2(TimedStroke s)
double	getHookAngleThresh() Return the threshold angle value for a hook.
void	setHookAngleThresh(double val) Set the threshold angle value for testing for a hook.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_ANGLE_THRESHOLD

public static final double DEFAULT_ANGLE_THRESHOLD

See Also:

Constant Field Values

Constructor Detail

DehookingStrokeFilter

public DehookingStrokeFilter()

Create a dehooking stroke filter with the default parameters.

Method Detail

apply

public TimedStroke apply(TimedStroke s)

Description copied from class: StrokeFilter

Apply a filtering algorithm on the specified pen stroke and return the filtered stroke.

Specified by:

apply in class StrokeFilter

dehook2

public static TimedStroke dehook2(TimedStroke s)

dehook

public static TimedStroke dehook(TimedStroke s)

At the beginning and the end of the given stroke, calculate the general direction vectors by taking the 2/10 of the total length from each end. Then start from 1/10 of the total length going toward the end of the stroke, compute the angle formed by the local vector and the general vector. If the angle value exceeds the DEFAULT_ANGLE_THRESH, eliminate the remaining points to get rid of the hook.

dehook

public static TimedStroke dehook(TimedStroke s,
                                 double angleThresh)

setHookAngleThresh

public void setHookAngleThresh(double val)

Set the threshold angle value for testing for a hook.

getHookAngleThresh

public double getHookAngleThresh()

Return the threshold angle value for a hook.