diva.sketch.toolbox

Class LineRecognizer

java.lang.Object

diva.sketch.toolbox.LineRecognizer

All Implemented Interfaces:

StrokeRecognizer

public class LineRecognizer
extends Object
implements StrokeRecognizer

This recognizer recognizes lines from strokes. It forms a line with the first and last points in a stroke, and for each point on the stroke, it calculates the distance of the point from the line and computes the confidence value based on the maximum distance.

Version:

$Revision: 1.4 $

Author:

Heloise Hse (hwawen@eecs.berkeley.edu)

Field Summary

Fields

Modifier and Type	Field and Description
static double	DEFAULT_DIST_THRESH
static String	LINE_TYPE_ID The type ID for lines.

Constructor Summary

Constructors

Constructor and Description
LineRecognizer()

Method Summary

Modifier and Type	Method and Description
RecognitionSet	strokeCompleted(TimedStroke s) Invoked when a stroke is completed.
RecognitionSet	strokeModified(TimedStroke s) Invoked when a stroke has been modified, for example, points have been added to the stroke.
RecognitionSet	strokeStarted(TimedStroke s) Invoked when a stroke starts.

Methods inherited from class java.lang.Object

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

Field Detail

LINE_TYPE_ID

public static final String LINE_TYPE_ID

The type ID for lines.

See Also:

Constant Field Values

DEFAULT_DIST_THRESH

public static final double DEFAULT_DIST_THRESH

See Also:

Constant Field Values

Constructor Detail

LineRecognizer

public LineRecognizer()

Method Detail

strokeCompleted

public RecognitionSet strokeCompleted(TimedStroke s)

Invoked when a stroke is completed. This occurs when the mouse up event has been detected. First, filter the input stroke. If there's only 1 data point (lineCheck result is -1), this is definitely not a line, confidence = 0. If there are 2 data points, create a SimpleData with LINE_TYPE_ID and confidence value of 1. If there are more than 2 points in the filtered stroke, form a line with the first and the last points, then for every point in between, calculate the distance between the point and the line, record the maximum distance (maxDist)from the line, then create a SimpleData with LINE_TYPE_ID and confidence value of * (1-maxDist/100).

Specified by:

strokeCompleted in interface StrokeRecognizer

strokeModified

public RecognitionSet strokeModified(TimedStroke s)

Invoked when a stroke has been modified, for example, points have been added to the stroke. It is probably safe to assume that this will be called every time a point is added to a stroke.

Specified by:

strokeModified in interface StrokeRecognizer

strokeStarted

public RecognitionSet strokeStarted(TimedStroke s)

Invoked when a stroke starts. This occurs when the mouse down event has been detected.

Specified by:

strokeStarted in interface StrokeRecognizer