<dependency>
	<groupId>net.coobird</groupId>
	<artifactId>thumbnailator</artifactId>
	<version>0.4.8</version>
</dependency>

/**
 * 橫坐標(biāo)
 */
private static final int x = 457;
/**
 * 縱坐標(biāo)
 */
private static final int y = 295;
/**
 * 旋轉(zhuǎn)角度
 */
private static final double angle = 16;
/**
 * 縮放比例
 */
private static final double scale = 0.18;
/**
 * 圖片合成
 *
 * @param imagePath 待合成的圖片路徑
 * @param outPath 合成后的圖片輸出路徑
 * @throws IOException
 */
private static void synthesis(String imagePath, String outPath) throws IOException {
	// 模板圖
	BufferedImage template = ImageIO.read(new File("D:\\local\\images\\template.png"));
	// 待合成圖
	BufferedImage image = ImageIO.read(new File(imagePath));
	// 調(diào)整待合成圖的尺寸和旋轉(zhuǎn)角度
	image = Thumbnails.of(image).scale(scale).rotate(angle).asBufferedImage();
	// 合成后的圖
	BufferedImage result = new BufferedImage(template.getWidth(), template.getHeight(), template.getType());
	Graphics2D graphics2D = result.createGraphics();
	// 先畫待合成圖，后畫模板圖，這樣就能將待合成圖放置在模板圖的下層
	graphics2D.drawImage(image, x, y, null);
	graphics2D.drawImage(template,0,0, null);
	graphics2D.dispose();
	ImageIO.write(result, "png", new File(outPath));
}

public static void main(String[] args) throws IOException {
	synthesis("D:\\local\\images\\weixin_payment_code.png", "D:\\local\\images\\result.png");
}

/**
 * 調(diào)整亮度、對(duì)比度
 *
 * @param image
 */
private static void adjustBrightnessAndContrast(BufferedImage image) {
	int width = image.getWidth();
	int height = image.getHeight();
	for (int x = 0; x < width; x++) {
		for (int y = 0; y < height; y++) {
			Color color = new Color(image.getRGB(x, y));
			int red = calculateColor(color.getRed());
			int green = calculateColor(color.getGreen());
			int blue = calculateColor(color.getBlue());
			color = new Color(red, green, blue);
			image.setRGB(x, y, color.getRGB());
		}
	}
}
/**
 * 亮度，取值范圍[-1,1]
 */
private static final double BRIGHTNESS = 0;
/**
 * 對(duì)比度，取值范圍[-1,1]
 */
private static final double CONTRAST = -0.5;
/**
 * 計(jì)算亮度、對(duì)比度顏色值
 *
 * @param color 原顏色值
 * @return 返回計(jì)算后的顏色值
 */
private static int calculateColor(int color) {
	color = (int)((color - 127.5 * (1 - BRIGHTNESS)) * Math.tan((45 + 44 * CONTRAST) / 180 * Math.PI) + 127.5 * (1 + BRIGHTNESS));
	return getColor(color);
}
/**
 * 獲取范圍內(nèi)的顏色值，[0,255]
 *
 * @param color
 * @return
 */
private static int getColor(int color) {
	return color > 255 ? 255 : color < 0 ? 0 : color;
}

...
// 調(diào)整待合成圖的尺寸和旋轉(zhuǎn)角度
image = Thumbnails.of(image).scale(scale).rotate(angle).asBufferedImage();
// 調(diào)整待合成圖片的亮度、對(duì)比度
adjustBrightnessAndContrast(image);
...