فیلتر Min در جاوا (minimum filter in java)

public class MinFilter {
	public static void main(String[] args) {
		BufferedImage img = null;
		File f = null;
		// read image
		try {
			f = new File("Min Filter input.png");
			img = ImageIO.read(f);
		} catch (IOException e) {
			System.out.println(e);
		}
		// get width and height
		int width = img.getWidth();
		int height = img.getHeight();
		BufferedImage outputimage = new 
BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
		System.out.println("Min Filter starts....");
		for (int x = 1; x < width - 1; x++) {
			for (int y = 1; y < height - 1; y++) {
				int maxred = 0;
				int maxgreen = 0;
				int maxblue = 0;
				maxred = MinRed(img, x, y);
				maxgreen = MinGreen(img, x, y);
				maxblue = MinBlue(img, x, y);
				Color col = new Color(maxred, maxgreen, maxblue);
				outputimage.setRGB(x, y, col.getRGB());
			}
		}
		System.out.println("start create output image....");
		// write image
		try {
			f = new File("Min Filter output.png");
			ImageIO.write(outputimage, "png", f);
		} catch (IOException e) {
			System.out.println(e);
		}
		System.out.println("program finish....");
	}
	private static int MinRed(BufferedImage img, int x, int y) {
		int neighbour[] = new int[9];
		neighbour[0] = getRed(img.getRGB(x - 1, y - 1));
		neighbour[1] = getRed(img.getRGB(x + 1, y + 1));
		neighbour[2] = getRed(img.getRGB(x, y - 1));
		neighbour[3] = getRed(img.getRGB(x, y + 1));
		neighbour[4] = getRed(img.getRGB(x - 1, y));
		neighbour[5] = getRed(img.getRGB(x + 1, y));
		neighbour[6] = getRed(img.getRGB(x - 1, y + 1));
		neighbour[7] = getRed(img.getRGB(x + 1, y - 1));
		neighbour[8] = getRed(img.getRGB(x, y));
		Arrays.sort(neighbour);
		return neighbour[0];
	}
	private static int MinBlue(BufferedImage img, int x, int y) {
		int neighbour[] = new int[9];
		neighbour[0] = getBlue(img.getRGB(x - 1, y - 1));
		neighbour[1] = getBlue(img.getRGB(x + 1, y + 1));
		neighbour[2] = getBlue(img.getRGB(x, y - 1));
		neighbour[3] = getBlue(img.getRGB(x, y + 1));
		neighbour[4] = getBlue(img.getRGB(x - 1, y));
		neighbour[5] = getBlue(img.getRGB(x + 1, y));
		neighbour[6] = getBlue(img.getRGB(x - 1, y + 1));
		neighbour[7] = getBlue(img.getRGB(x + 1, y - 1));
		neighbour[8] = getBlue(img.getRGB(x, y));
		Arrays.sort(neighbour);
		return neighbour[0];
	}
	private static int MinGreen(BufferedImage img, int x, int y) {
		int neighbour[] = new int[9];
		neighbour[0] = getGreen(img.getRGB(x - 1, y - 1));
		neighbour[1] = getGreen(img.getRGB(x + 1, y + 1));
		neighbour[2] = getGreen(img.getRGB(x, y - 1));
		neighbour[3] = getGreen(img.getRGB(x, y + 1));
		neighbour[4] = getGreen(img.getRGB(x - 1, y));
		neighbour[5] = getGreen(img.getRGB(x + 1, y));
		neighbour[6] = getGreen(img.getRGB(x - 1, y + 1));
		neighbour[7] = getGreen(img.getRGB(x + 1, y - 1));
		neighbour[8] = getGreen(img.getRGB(x, y));
		Arrays.sort(neighbour);
		return neighbour[0];
	}
	public static int getRed(int rgb) {
		return (rgb >> 16) & 0xff;
	}
	public static int getBlue(int rgb) {
		return rgb & 0xff;
	}
	public static int getGreen(int rgb) {
		return (rgb >> 8) & 0xff;
	}
}