code: public int getUnsignedPixelValue(BufferedImage image, int x, int y) {
  		short pixelValue = getPixelValue(image, x, y);
  		int unsignedPixelValue = getUnsignedPixelValue(pixelValue);
  		return unsignedPixelValue;
  	}
docs: Get the pixel value as a 16 bit unsigned integer value
  
  @param image
  tile image
  @param x
  x coordinate
  @param y
  y coordinate
  @return unsigned integer pixel value