画象diff | Codetter（こーどったー）

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;

public class ImageDiff {

	// 入力ファイル
	public static final String INPUT1 = "data/input1.jpg";
	public static final String INPUT2 = "data/input2.jpg";

	// 出力ファイル
	public static final String OUTPUT = "data/output.jpg";

	// 操作用画象
	private static BufferedImage image1;
	private static BufferedImage image2;
	private static BufferedImage output;

	public static void main(String[] args) {
		loadImage();
		doProcess();
		saveImage();
	}

	/**
	 * 画象処理
	 */
	private static void doProcess() {
		int width = Math.max(image1.getWidth(), image2.getWidth());
		int height = Math.max(image1.getHeight(), image2.getHeight());
		output = new BufferedImage(width, height, BufferedImage.TYPE_3BYTE_BGR);

		for (int x = 0; x < width; x++) {
			for (int y = 0; y < height; y++) {
				int rgb1;
				if ((x <= image1.getWidth()) && (y <=image1.getHeight())) {
					rgb1 = image1.getRGB(x, y);
				} else {
					rgb1 = 0;
				}
				int rgb2;
				if ((x <= image2.getWidth()) && (y <=image2.getHeight())) {
					rgb2 = image2.getRGB(x, y);
				} else {
					rgb2 = 0;
				}
				int diff = rgb1 - rgb2;
				output.setRGB(x, y, diff);
			}
		}
	}

	/**
	 * 画像の読み込み
	 */
	private static void loadImage() {
		try {
			image1 = ImageIO.read(new File(INPUT1));
			image2 = ImageIO.read(new File(INPUT2));
		} catch (Exception e) {
			e.printStackTrace();
			System.exit(1);
		}

	}

	/**
	 * 画像書き込み
	 */
	private static void saveImage() {
		try {
			ImageIO.write(output, "jpg", new File(OUTPUT));
		} catch (IOException e) {
			e.printStackTrace();
			System.exit(1);
		}
	}
}