Updated LetterRecognizer & related gesture recognition code (e6ea003a) · Commits · e / os / android_frameworks_base

tests/sketch/src/com/android/gesture/GestureLibrary.java

+8 −8

Original line number	Diff line number	Diff line
		@@ -49,11 +49,11 @@ public class GestureLibrary {
		private static final String NAMESPACE = "";

		public static final int SEQUENCE_INVARIANT = 1;
		// when SEQUENCE_SENSITIVE is used, only single stroke gestures are allowed
		// when SEQUENCE_SENSITIVE is used, only single stroke gestures are currently allowed
		public static final int SEQUENCE_SENSITIVE = 2;

		// ORIENTATION_SENSITIVE and ORIENTATION_INVARIANT are only for SEQUENCE_SENSITIVE gestures
		public static final int ORIENTATION_INVARIANT = 1;
		// ORIENTATION_SENSITIVE is only available for single stroke gestures
		public static final int ORIENTATION_SENSITIVE = 2;

		private int mSequenceType = SEQUENCE_SENSITIVE;
		@@ -77,8 +77,8 @@ public class GestureLibrary {
		}

		/**
		* Specify whether the gesture library will handle orientation sensitive
		* gestures. Use ORIENTATION_INVARIANT or ORIENTATION_SENSITIVE
		* Specify how the gesture library will handle orientation.
		* Use ORIENTATION_INVARIANT or ORIENTATION_SENSITIVE
		*
		* @param style
		*/
		@@ -114,8 +114,8 @@ public class GestureLibrary {
		* @return a list of predictions of possible entries for a given gesture
		*/
		public ArrayList<Prediction> recognize(Gesture gesture) {
		Instance instance = Instance.createInstance(this, gesture, null);
		return mClassifier.classify(this, instance);
		Instance instance = Instance.createInstance(mSequenceType, gesture, null);
		return mClassifier.classify(mSequenceType, instance.vector);
		}

		/**
		@@ -134,7 +134,7 @@ public class GestureLibrary {
		mEntryName2gestures.put(entryName, gestures);
		}
		gestures.add(gesture);
		mClassifier.addInstance(Instance.createInstance(this, gesture, entryName));
		mClassifier.addInstance(Instance.createInstance(mSequenceType, gesture, entryName));
		mChanged = true;
		}

		@@ -300,7 +300,7 @@ public class GestureLibrary {
		mGestures = null;
		} else if (localName.equals(GestureConstants.XML_TAG_GESTURE)) {
		mGestures.add(mCurrentGesture);
		mClassifier.addInstance(Instance.createInstance(GestureLibrary.this,
		mClassifier.addInstance(Instance.createInstance(mSequenceType,
		mCurrentGesture, mEntryName));
		mCurrentGesture = null;
		} else if (localName.equals(GestureConstants.XML_TAG_STROKE)) {

tests/sketch/src/com/android/gesture/GestureStroke.java

+8 −0

Original line number	Diff line number	Diff line
		@@ -244,4 +244,12 @@ public class GestureStroke {
		public void invalidate() {
		mCachedPath = null;
		}

		/**
		* Compute an oriented bounding box of the stroke
		* @return OrientedBoundingBox
		*/
		public OrientedBoundingBox computeOrientedBoundingBox() {
		return GestureUtilities.computeOrientedBoundingBox(points);
		}
		}

tests/sketch/src/com/android/gesture/GestureUtilities.java

+8 −10

Original line number	Diff line number	Diff line
		@@ -26,7 +26,7 @@ import java.io.IOException;

		import static com.android.gesture.GestureConstants.*;

		public final class GestureUtilities {
		final class GestureUtilities {
		private static final int TEMPORAL_SAMPLING_RATE = 16;

		private GestureUtilities() {
		@@ -348,33 +348,31 @@ public final class GestureUtilities {
		/**
		* Calculate the cosine distance between two instances
		*
		* @param in1
		* @param in2
		* @param vector1
		* @param vector2
		* @return the distance between 0 and Math.PI
		*/
		static double cosineDistance(Instance in1, Instance in2) {
		static double cosineDistance(float[] vector1, float[] vector2) {
		float sum = 0;
		float[] vector1 = in1.vector;
		float[] vector2 = in2.vector;
		int len = vector1.length;
		for (int i = 0; i < len; i++) {
		sum += vector1[i] * vector2[i];
		}
		return Math.acos(sum / (in1.magnitude * in2.magnitude));
		return Math.acos(sum);
		}

		public static OrientedBoundingBox computeOrientedBoundingBox(ArrayList<GesturePoint> pts) {
		static OrientedBoundingBox computeOrientedBoundingBox(ArrayList<GesturePoint> pts) {
		GestureStroke stroke = new GestureStroke(pts);
		float[] points = temporalSampling(stroke, TEMPORAL_SAMPLING_RATE);
		return computeOrientedBoundingBox(points);
		}

		public static OrientedBoundingBox computeOrientedBoundingBox(float[] points) {
		static OrientedBoundingBox computeOrientedBoundingBox(float[] points) {
		float[] meanVector = computeCentroid(points);
		return computeOrientedBoundingBox(points, meanVector);
		}

		public static OrientedBoundingBox computeOrientedBoundingBox(float[] points, float[] centroid) {
		static OrientedBoundingBox computeOrientedBoundingBox(float[] points, float[] centroid) {
		Matrix tr = new Matrix();
		tr.setTranslate(-centroid[0], -centroid[1]);
		tr.mapPoints(points);

tests/sketch/src/com/android/gesture/Instance.java

+21 −13

Original line number	Diff line number	Diff line
		@@ -23,7 +23,7 @@ package com.android.gesture;
		class Instance {
		private static final int SEQUENCE_SAMPLE_SIZE = 16;

		private static final int PATCH_SAMPLE_SIZE = 8;
		private static final int PATCH_SAMPLE_SIZE = 16;

		private final static float[] ORIENTATIONS = {
		0, 45, 90, 135, 180, -0, -45, -90, -135, -180
		@@ -35,9 +35,6 @@ class Instance {
		// the label can be null
		final String label;

		// the length of the vector
		final float magnitude;

		// the id of the instance
		final long id;

		@@ -45,12 +42,19 @@ class Instance {
		this.id = id;
		vector = sample;
		label = sampleName;
		}

		private void normalize() {
		float[] sample = vector;
		float sum = 0;
		int size = sample.length;
		for (int i = 0; i < size; i++) {
		sum += sample[i] * sample[i];
		}
		magnitude = (float) Math.sqrt(sum);
		float magnitude = (float) Math.sqrt(sum);
		for (int i = 0; i < size; i++) {
		sample[i] /= magnitude;
		}
		}

		/**
		@@ -60,21 +64,25 @@ class Instance {
		* @param label
		* @return the instance
		*/
		static Instance createInstance(GestureLibrary gesturelib, Gesture gesture, String label) {
		static Instance createInstance(int samplingType, Gesture gesture, String label) {
		float[] pts;
		if (gesturelib.getGestureType() == GestureLibrary.SEQUENCE_SENSITIVE) {
		pts = temporalSampler(gesturelib, gesture);
		Instance instance;
		if (samplingType == GestureLibrary.SEQUENCE_SENSITIVE) {
		pts = temporalSampler(samplingType, gesture);
		instance = new Instance(gesture.getID(), pts, label);
		instance.normalize();
		} else {
		pts = spatialSampler(gesture);
		instance = new Instance(gesture.getID(), pts, label);
		}
		return new Instance(gesture.getID(), pts, label);
		return instance;
		}

		private static float[] spatialSampler(Gesture gesture) {
		return GestureUtilities.spatialSampling(gesture, PATCH_SAMPLE_SIZE);
		}

		private static float[] temporalSampler(GestureLibrary gesturelib, Gesture gesture) {
		private static float[] temporalSampler(int samplingType, Gesture gesture) {
		float[] pts = GestureUtilities.temporalSampling(gesture.getStrokes().get(0),
		SEQUENCE_SAMPLE_SIZE);
		float[] center = GestureUtilities.computeCentroid(pts);
		@@ -82,7 +90,7 @@ class Instance {
		orientation *= 180 / Math.PI;

		float adjustment = -orientation;
		if (gesturelib.getOrientationStyle() == GestureLibrary.ORIENTATION_SENSITIVE) {
		if (samplingType == GestureLibrary.ORIENTATION_SENSITIVE) {
		int count = ORIENTATIONS.length;
		for (int i = 0; i < count; i++) {
		float delta = ORIENTATIONS[i] - orientation;

tests/sketch/src/com/android/gesture/InstanceLearner.java

+5 −5

Original line number	Diff line number	Diff line
		@@ -34,21 +34,21 @@ class InstanceLearner extends Learner {
		private static final String LOGTAG = "InstanceLearner";

		@Override
		ArrayList<Prediction> classify(GestureLibrary lib, Instance instance) {
		ArrayList<Prediction> classify(int gestureType, float[] vector) {
		ArrayList<Prediction> predictions = new ArrayList<Prediction>();
		ArrayList<Instance> instances = getInstances();
		int count = instances.size();
		TreeMap<String, Double> label2score = new TreeMap<String, Double>();
		for (int i = 0; i < count; i++) {
		Instance sample = instances.get(i);
		if (sample.vector.length != instance.vector.length) {
		if (sample.vector.length != vector.length) {
		continue;
		}
		double distance;
		if (lib.getGestureType() == GestureLibrary.SEQUENCE_SENSITIVE) {
		distance = GestureUtilities.cosineDistance(sample, instance);
		if (gestureType == GestureLibrary.SEQUENCE_SENSITIVE) {
		distance = GestureUtilities.cosineDistance(sample.vector, vector);
		} else {
		distance = GestureUtilities.squaredEuclideanDistance(sample.vector, instance.vector);
		distance = GestureUtilities.squaredEuclideanDistance(sample.vector, vector);
		}
		double weight;
		if (distance == 0) {