Two basic filters: highpass and lowpass to either remove rapid movements or slow movements.

git-svn-id: svn://svn.code.sf.net/p/wiigee/code/trunk@77 c7eff9ee-dd40-0410-8832-91a4d88773cf

src/device/Device.java

@@ -56,9 +56,9 @@ public class Device {
 	protected ProcessingUnit processingunit = new TriggeredProcessingUnit();//new TriggeredProcessingUnit();
 	
 	public Device() {
-		this.addFilter(new IdleStateFilter());
-		this.addFilter(new MotionDetectFilter(this));
-		this.addFilter(new DirectionalEquivalenceFilter());
+		//this.addFilter(new IdleStateFilter());
+		//this.addFilter(new MotionDetectFilter(this));
+		//this.addFilter(new DirectionalEquivalenceFilter());
 		this.addDeviceListener(this.processingunit);
 	}
 	

src/filter/HighPassFilter.java

@@ -0,0 +1,66 @@
+/*
+ * wiigee - accelerometerbased gesture recognition
+ * Copyright (C) 2007, 2008, 2009 Benjamin Poppinga
+ *
+ * Developed at University of Oldenburg
+ * Contact: benjamin.poppinga@informatik.uni-oldenburg.de
+ *
+ * This file is part of wiigee.
+ *
+ * wiigee is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+package filter;
+
+/**
+ *
+ * This filter removes every acceleration that happens slowly or
+ * steadily (like e.g. gravity). Remember: It _passes_ acceleration
+ * with a big variety.
+ *
+ * @author Benjamin 'BePo' Poppinga
+ */
+public class HighPassFilter extends Filter {
+
+    private double factor;
+    private double[] prevAcc;
+
+    public HighPassFilter() {
+        super();
+        this.factor = 0.1;
+        this.prevAcc = new double[] {0.0, 0.0, 0.0};
+    }
+
+    public HighPassFilter(double factor) {
+        super();
+        this.factor = factor;
+        this.prevAcc = new double[] {0.0, 0.0, 0.0};
+    }
+
+    @Override
+    public double[] filterAlgorithm(double[] vector) {
+        double[] retVal = new double[3];
+        prevAcc[0] = vector[0] * this.factor + this.prevAcc[0] * (1.0 - this.factor);
+        prevAcc[1] = vector[1] * this.factor + this.prevAcc[1] * (1.0 - this.factor);
+        prevAcc[2] = vector[2] * this.factor + this.prevAcc[2] * (1.0 - this.factor);
+
+        retVal[0] = vector[0] - prevAcc[0];
+        retVal[1] = vector[1] - prevAcc[1];
+        retVal[2] = vector[2] - prevAcc[2];
+        
+        return retVal;
+    }
+
+}

src/filter/LowPassFilter.java

@@ -0,0 +1,62 @@
+/*
+ * wiigee - accelerometerbased gesture recognition
+ * Copyright (C) 2007, 2008, 2009 Benjamin Poppinga
+ *
+ * Developed at University of Oldenburg
+ * Contact: benjamin.poppinga@informatik.uni-oldenburg.de
+ *
+ * This file is part of wiigee.
+ *
+ * wiigee is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+package filter;
+
+/**
+ *
+ * This filter removes every acceleration that happens fast or
+ * suddenly (like e.g. a short hit). Remember: It _passes_ acceleration
+ * with a slight variety.
+ *
+ * @author Benjamin 'BePo' Poppinga
+ */
+public class LowPassFilter extends Filter {
+
+    private double factor;
+    private double[] prevAcc;
+
+    public LowPassFilter() {
+        super();
+        this.factor = 0.01;
+        this.prevAcc = new double[] {0.0, 0.0, 0.0};
+    }
+
+    public LowPassFilter(double factor) {
+        super();
+        this.factor = factor;
+        this.prevAcc = new double[] {0.0, 0.0, 0.0};
+    }
+
+    @Override
+    public double[] filterAlgorithm(double[] vector) {
+        double[] retVal = new double[3];
+        retVal[0] = vector[0] * this.factor + this.prevAcc[0] * (1.0 - this.factor);
+        retVal[1] = vector[1] * this.factor + this.prevAcc[1] * (1.0 - this.factor);
+        retVal[2] = vector[2] * this.factor + this.prevAcc[2] * (1.0 - this.factor);
+        this.prevAcc = retVal;
+        return retVal;
+    }
+
+}