public static BufferedImage doFilter(BufferedImage img) {
BufferedImage img2 =
new BufferedImage(img.getWidth(), img.getHeight(), BufferedImage.TYPE_3BYTE_BGR);
// img.getSubimage(0, 0, img.getWidth(), img.getHeight());
for (int i = 0; i < img2.getWidth(); i++) {
for (int j = 0; j < img2.getHeight(); j++) {
img2.setRGB(i, j, img.getRGB(i, j));
// img2.setRGB(i, j, Color.BLACK.getRGB());
}
}
int a = 32;
for (int j = 0; j < img2.getHeight(); j++) {
for (int i = 0; i < img2.getWidth(); i++) {
int c = img.getRGB(i, j);
Color c2 = new Color(c);
Error er = new Error();
er.r = (int) (a * matrix[i % 2][j % 2]);
er.g = er.r;
er.b = er.r;
c2 = addToPixel(c2, er, 1);
Color c3 = getClosestPixel(c2);
setPixel(img2, i, j, c3);
// oldpixel := pixel[x][y] + threshold_map_4x4[x mod 4][y mod 4]
// newpixel := find_closest_palette_color(oldpixel)
// pixel[x][y] := newpixel
}
}
return img2;
}
private static Error getError(Color c1, Color c2) {
int r = c1.getRed();
int g = c1.getGreen();
int b = c1.getBlue();
r = r - c2.getRed();
g = g - c2.getGreen();
b = b - c2.getBlue();
Error er = new Error();
er.r = r;
er.g = g;
er.b = b;
return er;
}
