create random image

RandomImage.java

package imagexx;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

public class RandomImage {
    public static void main(String args[]) {
        int width = 640;
        int height = 320;
        int pixelSize = 20;
        BufferedImage img = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);

        int yp = height / pixelSize;
        int xp = width / pixelSize;

        for (int yi = 0; yi < yp; yi++) {
            for (int xi = 0; xi < xp; xi++) {
                int rgb = createRandomRGB();
                drawPixel(img, yi, xi, pixelSize, rgb);
            }
        }

        Graphics graphics = img.getGraphics();
        graphics.setColor(Color.BLACK);
        graphics.setFont(new Font("Arial", Font.BOLD, 60));
        graphics.drawString("123456", 0, height/2);

        try {
            File f = new File("Output.png");
            ImageIO.write(img, "png", f);
        } catch (IOException e) {
            System.out.println("Error: " + e);
        }
    }

    private static void drawPixel(BufferedImage img, int yi, int xi, int pixelSize, int p) {
        for (int y = yi * pixelSize, yy = y + pixelSize; y < yy; y++) {
            for (int x = xi * pixelSize,xx = x + pixelSize; x < xx; x++) {
                img.setRGB(x, y, p);
            }
        }
    }

    private static int createRandomRGB() {
        int a = (int) (Math.random() * 256); //alpha
        int r = (int) (Math.random() * 256); //red
        int g = (int) (Math.random() * 256); //green
        int b = (int) (Math.random() * 256); //blue

        return (a << 24) | (r << 16) | (g << 8) | b;
    }
}