Tile Image

package image;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.net.URL;

import javax.imageio.ImageIO;

public class ImageTest {
    public static void main(String[] args) {
        tileImage("mister.png", "mister_tile.png", 0xDDAA33, false, 4, 4, 20, 20, 15, 12);
        tileImage("mister.png", "mister_tile2.png", 0xFF69A6, false, 1, 2, 100);
    }

    public static void tileImage(String inputFilename, String outputFilename,
            int bgColor, boolean transparent, int spacing, int border,
            int tileCount) {
        tileImage(inputFilename, outputFilename, bgColor, transparent, spacing,
                spacing, border, border, tileCount, tileCount);
    }

    public static void tileImage(String inputFilename, String outputFilename,
            int bgColor, boolean transparent, int spacingX, int spacingY,
            int borderX, int borderY, int tileCountX, int tileCountY) {
        BufferedImage srcImg = loadImage(inputFilename);
        int imgType = srcImg.getType();
        Color fill = new Color(bgColor, transparent);
        int width = srcImg.getWidth();
        int height = srcImg.getHeight();
        int tileWidth = width / tileCountX;
        int tileHeight = height / tileCountY;
        int calcWidth = width + (spacingX * (tileCountX - 1)) + (borderX * 2);
        int calcHeight = height + (spacingY * (tileCountY - 1)) + (borderY * 2);
        int diffWidth = width - tileWidth * tileCountX;
        int diffHeight = height - tileHeight * tileCountY;
        int newWidth = calcWidth - diffWidth;
        int newHeight = calcHeight - diffHeight;
        BufferedImage outImg = new BufferedImage(newWidth, newHeight, imgType);
        Graphics g = outImg.getGraphics();

        g.setColor(fill);
        g.fillRect(0, 0, newWidth, newHeight);

        for (int row = 0; row < tileCountY; row++) {
            for (int col = 0; col < tileCountX; col++) {
                int dX = col * tileWidth;
                int dY = row * tileHeight;
                BufferedImage tile = srcImg.getSubimage(dX, dY, tileWidth, tileHeight);
                int offX = (col * (tileWidth + spacingX)) + borderX;
                int offY = (row * (tileHeight + spacingY)) + borderY;
                g.drawImage(tile, offX, offY, null);
            }
        }

        writeImage(outImg, "tile", outputFilename);
    }

    public static BufferedImage loadImage(String filename) {
        URL url = null;
        try {
            ClassLoader loader = CommonUtil.class.getClassLoader();
            url = loader.getResource("resources/" + filename);
            return ImageIO.read(url);
        } catch (Exception e) {
            System.err.println("Could not load image: " + url);
        }
        return null;
    }

    public static void writeImage(BufferedImage img, String directory, String filename) {
        try {
            StringBuffer path = new StringBuffer();
            if (directory != null && !directory.isEmpty()) {
                path.append(directory).append('\\');
            }
            path.append(filename);
            File outputfile = new File(path.toString());
            // http://stackoverflow.com/a/2833883/1762224
            outputfile.getParentFile().mkdirs();
            ImageIO.write(img, "png", outputfile);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}