public static void main(String[] args) {
		if (args.length == 0) {
			System.out.println("usage:  java Blur imagefile [iterations]");
			System.out.println("  imagefile is an image in TIFF format.");
			System.out
					.println("  interations is the number of blurring iterations"
							+ " (default 1).");
			System.out
					.println("The blurred image is written to blur_imagefile.");
			System.exit(0);
		}

		int numIterations = 1;
		if (args.length > 1) {
			try {
				numIterations = Integer.parseInt(args[1]);
			} catch (NumberFormatException ex) {
				System.err.println("The second argument must be a number.");
				System.exit(1);
			}
		}

		blurFile(args[0], numIterations);
	}