public static int[] getPixels(BufferedImage img,
                                  int x, int y, int w, int h, int[] pixels) {
        if (w == 0 || h == 0) {
            return new int[0];
        }

        if (pixels == null) {
            pixels = new int[w * h];
        } else if (pixels.length < w * h) {
            throw new IllegalArgumentException("pixels array must have a length" +
                                               " >= w*h");
        }

        int imageType = img.getType();
        if (imageType == BufferedImage.TYPE_INT_ARGB ||
            imageType == BufferedImage.TYPE_INT_RGB) {
            Raster raster = img.getRaster();
            return (int[]) raster.getDataElements(x, y, w, h, pixels);
        }

        // Unmanages the image
        return img.getRGB(x, y, w, h, pixels, 0, w);
    }