public static BufferedImage toGrayScale(BufferedImage image) {
BufferedImage result =
new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_BYTE_GRAY);
Raster raster = image.getData();
WritableRaster grayRaster = result.getRaster();
int height = raster.getHeight();
int sample = 0;
for (int x = 0; x < raster.getWidth(); ++x) {
for (int y = 0; y < height; ++y) {
sample = raster.getSample(x, y, 0) + raster.getSample(x, y, 1) + raster.getSample(x, y, 2);
grayRaster.setSample(x, y, 0, (int) ((float) sample / 3.0));
}
}
return result;
}
// 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)));
}