/*
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*/
package it.freedomotic.plugins.webcam;
import java.awt.Image;
import java.awt.image.ImageObserver;
import java.awt.image.PixelGrabber;
/**
*
* @author Enrico Nicoletti
*/
public class SimpleMotionDetector extends MotionDetector {
int oldSum;
private int[] previousPixels = null;
private int[] latestPixels = null;
private int motionLevel;
int frameNo = 0;
public SimpleMotionDetector() {
super();
}
public int enqueueImage(Image latest) {
int w = latest.getWidth(null);
int h = latest.getHeight(null);
//First time we run this function allocate the array
if (latestPixels == null) {
latestPixels = new int[w * h];
}
if (previousPixels == null) {
previousPixels = new int[w * h];
}
PixelGrabber latestPixelGrabber = new PixelGrabber(latest, 0, 0, w, h, latestPixels, 0, w);
try {
latestPixelGrabber.grabPixels();
} catch (InterruptedException e) {
System.out.println("interrupted waiting for pixels");
}
if ((latestPixelGrabber.getStatus() & ImageObserver.ABORT) != 0) {
System.out.println("image fetch aborted or errored");
}
if (previousPixels != null) {
motionLevel = 0;
for (int ct = 0; ct < (w * h); ct++) {
int latestPixel = latestPixels[ct];
int latestAlpha = (latestPixel >> 24) & 0xff;
int latestRed = (latestPixel >> 16) & 0xff;
int latestGreen = (latestPixel >> 8) & 0xff;
int latestBlue = (latestPixel) & 0xff;
int previousPixel = previousPixels[ct];
int previousAlpha = (previousPixel >> 24) & 0xff;
int previousRed = (previousPixel >> 16) & 0xff;
int previousGreen = (previousPixel >> 8) & 0xff;
int previousBlue = (previousPixel) & 0xff;
if ((Math.abs(previousRed - latestRed) > noiseThreshold) | (Math.abs(previousGreen - latestGreen) > noiseThreshold) | (Math.abs(previousBlue - latestBlue) > noiseThreshold)) {
motionLevel++;
}
}
}
System.arraycopy(latestPixels, 0, previousPixels, 0, latestPixels.length);
try {
Thread.sleep(100);
} catch (InterruptedException e) {
}
//Normalise motion level to be in the range 0-999
int noOfPixels = w * h;
motionLevel = (motionLevel * 1000) / noOfPixels;
//return no motion for first few frames to avoid initial motion spike
if (frameNo < 5) {
frameNo++;
return 0;
}
return motionLevel;
}
}