fr.lri.swingstates.gestures.dtw

Class DTWClassifier

java.lang.Object

fr.lri.swingstates.gestures.AbstractClassifier

fr.lri.swingstates.gestures.dtw.DTWClassifier

public class DTWClassifier
extends AbstractClassifier

A very simple recognizer that performs simple shape matching based on a single example per class (one template):

1. Resample the gesture to classify so it contains the number of uniformly spaced points as the gesture templates contained in this classifier.
2. For each template, scale the input gesture so its bounding box matches the bounding box of the template and compute the sum of distances point to point between the template points and the input gesture points.
3. Returns the name of the class for the template that minimizes this sum of distances.

Author:

Caroline Appert

Constructor Summary

Constructors

Constructor and Description
DTWClassifier()

Method Summary

Methods

Modifier and Type	Method and Description
int	addClass(java.lang.String className) Adds a class of gestures to this classifier.
void	addClass(java.lang.String className, java.util.Vector<java.awt.geom.Point2D> template) Adds a class and set the template for this class.
void	addExample(java.lang.String className, Gesture example) Adds a gesture example to this classifier.
java.lang.String	classify(Gesture g) Recognizes a gesture.
double	distance(Gesture gesture, java.lang.String gesture2)
double	distance(java.lang.String gesture1, java.lang.String gesture2)
double	distance(java.util.Vector<java.awt.geom.Point2D> inputPoints, java.lang.String gesture2)
double	distance(java.util.Vector<java.awt.geom.Point2D> inputPoints1, java.util.Vector<java.awt.geom.Point2D> inputPoints2)
java.util.Vector<Gesture>	getExamples(java.lang.String className) Returns the vector of gesture examples for a given class.
static DTWClassifier	newClassifier(java.io.File filename) Builds a new classifier by loading its definition in a file.
static DTWClassifier	newClassifier(java.lang.String file) Builds a new classifier by loading its definition in a file.
static DTWClassifier	newClassifier(java.net.URL url) Builds a new classifier by loading its definition in a url.
void	removeClass(java.lang.String className) Removes a class of gestures from this classifier.
void	removeExample(Gesture example) Removes a gesture example from this classifier.
void	renameClass(java.lang.String previousClassName, java.lang.String newClassName) Renames a class of gestures.
void	reset() Resets this classifier (i.e.
void	save(java.io.File filename) Saves the definition of this classifier in a file.
java.util.Vector<Score>	sortedClasses(Gesture g) Computes a sorted list of classes contained in this recognizer from the best match to the the worst match given a gesture.

Methods inherited from class fr.lri.swingstates.gestures.AbstractClassifier

addClassifierListener, fireClassAdded, fireClassRemoved, fireExampleAdded, fireExampleRemoved, fireTemplateSet, getClassesNames, getMinimumStrokeLength, getPngImage, getPngImage, getRepresentative, getTemplate, getTemplates, removeClassifierListener, setMinimumStrokeLength, setTemplate

Methods inherited from class java.lang.Object

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

Constructor Detail

DTWClassifier

public DTWClassifier()

Method Detail

distance

public double distance(java.lang.String gesture1,
              java.lang.String gesture2)

Specified by:

distance in class AbstractClassifier

distance

public double distance(Gesture gesture,
              java.lang.String gesture2)

distance

public double distance(java.util.Vector<java.awt.geom.Point2D> inputPoints,
              java.lang.String gesture2)

distance

public double distance(java.util.Vector<java.awt.geom.Point2D> inputPoints1,
              java.util.Vector<java.awt.geom.Point2D> inputPoints2)

classify

public java.lang.String classify(Gesture g)

Description copied from class: AbstractClassifier

Recognizes a gesture.

Specified by:

classify in class AbstractClassifier

Parameters:

g - The gesture to recognize

Returns:

The name of the class of gestures that best fit to g.

newClassifier

public static DTWClassifier newClassifier(java.lang.String file)

Builds a new classifier by loading its definition in a file.

Parameters:

file - The name of the file containing the definition of the classifier.

Returns:

The newly created classifier.

newClassifier

public static DTWClassifier newClassifier(java.io.File filename)

Builds a new classifier by loading its definition in a file.

Parameters:

filename - The name of the file containing the definition of the classifier.

Returns:

The newly created classifier.

newClassifier

public static DTWClassifier newClassifier(java.net.URL url)

Builds a new classifier by loading its definition in a url.

Parameters:

url - The url containing the definition of the classifier.

Returns:

The newly created classifier.

addClass

public int addClass(java.lang.String className)

Adds a class of gestures to this classifier.

Overrides:

addClass in class AbstractClassifier

Parameters:

className - The name of the class of gestures to add.

Returns:

the index of this class in the list of classes (-1 if this class already exists and thus has not been added).

renameClass

public void renameClass(java.lang.String previousClassName,
               java.lang.String newClassName)

Renames a class of gestures.

Overrides:

renameClass in class AbstractClassifier

Parameters:

previousClassName - The current name of this class of gestures

newClassName - The new name of this class of gestures

removeClass

public void removeClass(java.lang.String className)

Removes a class of gestures from this classifier.

Overrides:

removeClass in class AbstractClassifier

Parameters:

className - The name of the class of gestures to remove.

addClass

public void addClass(java.lang.String className,
            java.util.Vector<java.awt.geom.Point2D> template)

Adds a class and set the template for this class.

Parameters:

className - The name of the class to add

template - The template for the class className

sortedClasses

public java.util.Vector<Score> sortedClasses(Gesture g)

Computes a sorted list of classes contained in this recognizer from the best match to the the worst match given a gesture.

Specified by:

sortedClasses in class AbstractClassifier

Parameters:

g - The gesture

Returns:

a vector of scores for all the classes registered in this classifier sorted from the best match (index 0) to the worst match (index n-1), with n the number of classes. A score is a couple (class_name, distance).

save

public void save(java.io.File filename)

Saves the definition of this classifier in a file.

Overrides:

save in class AbstractClassifier

Parameters:

filename - The name of the file where to write the definition of the classifier.

removeExample

public void removeExample(Gesture example)

Removes a gesture example from this classifier.

Specified by:

removeExample in class AbstractClassifier

Parameters:

example - the gesture to remove

addExample

public void addExample(java.lang.String className,
              Gesture example)

Adds a gesture example to this classifier.

Specified by:

addExample in class AbstractClassifier

Parameters:

className - the gesture example's class

example - the gesture example

getExamples

public java.util.Vector<Gesture> getExamples(java.lang.String className)
                                      throws java.lang.UnsupportedOperationException

Returns the vector of gesture examples for a given class.

Specified by:

getExamples in class AbstractClassifier

Parameters:

className - The name of the class

Returns:

The set of examples for the class className.

Throws:

java.lang.UnsupportedOperationException

reset

public void reset()

Resets this classifier (i.e. removes all the classes of gestures).

Overrides:

reset in class AbstractClassifier