try {
	BufferedImage img = ImageIO.read(new File("C:\\terrain.png"));
	BufferedImage bmp = new BufferedImage(512, 512, BufferedImage.TYPE_INT_ARGB);
	Graphics bmpG = bmp.createGraphics();
	bmpG.drawImage(img, 0, 0, 512, 512, 0, 0, img.getWidth(), img.getHeight(), _
  null);
	bmpG.drawImage(img, 0, 0, null);
	ImageIO.write(bmp, "PNG", new File("C:\\terrainAusgabe.png"));
} catch (IOException e) {
	e.printStackTrace();
}