java 实现图像浮雕的方法

 public BufferedImage emboss(BufferedImage src) {
        int width = src.getWidth();
        int height = src.getHeight();

        BufferedImage dst;
        dst = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

        for (int i = 0; i < height; i++)
          for (int j = 0; j < width; j++) {
            int upperLeft = 0;
            int lowerRight = 0;

            if (i > 0 && j > 0)
              upperLeft = src.getRGB(j - 1, i - 1);

            if (i < height - 1 && j < width - 1)
              lowerRight = src.getRGB(j + 1, i + 1);

            int redDiff = ((lowerRight >> 16) & 255) - ((upperLeft >> 16) & 255);

            int greenDiff = ((lowerRight >> 8) & 255) - ((upperLeft >> 8) & 255);

            int blueDiff = (lowerRight & 255) - (upperLeft & 255);

            int diff = redDiff;
            if (Math.abs(greenDiff) > Math.abs(diff))
              diff = greenDiff;
            if (Math.abs(blueDiff) > Math.abs(diff))
              diff = blueDiff;