// returns a value specifying some kind of average brightness in the image.
protected int getAverageBrightness(BufferedImage img) {
Raster r = img.getData();
int total = 0;
for (int y = 0; y < r.getHeight(); y++) {
for (int x = 0; x < r.getWidth(); x++) {
total += r.getSample(r.getMinX() + x, r.getMinY() + y, 0);
}
}
return (int) (total / ((r.getWidth() / factorD) * (r.getHeight() / factorD)));
}
