private static void diffImages(BufferedImage goodImage,
			PixImage studentPixImage) {
		BufferedImage studentImage = ImageUtils
				.pixImage2buffer(studentPixImage);
		int diffCount = 0;
		System.out.println("The difference is:");
		if (studentImage.getWidth() != goodImage.getWidth()) {
			System.out.println("The width is " + studentImage.getWidth()
					+ " but should be " + goodImage.getWidth());
			diffCount++;
		}
		if (studentImage.getHeight() != goodImage.getHeight()) {
			System.out.println("The height is " + studentImage.getHeight()
					+ " but should be " + goodImage.getHeight());
			diffCount++;
		}
		for (int y = 0; y < goodImage.getHeight()
				&& y < studentImage.getHeight(); y++) {
			for (int x = 0; x < goodImage.getWidth()
					&& x < studentImage.getWidth(); x++) {
				if (goodImage.getRGB(x, y) != studentImage.getRGB(x, y)) {
					if (diffCount == MAX_PRINT_SIZE) {
						System.out.println("  ...");
						return;
					}
					System.out.println("  (" + x + "," + y + ") is "
							+ new Color(studentImage.getRGB(x, y))
							+ " but should be "
							+ new Color(goodImage.getRGB(x, y)));
					diffCount++;
				}
			}
		}
	}