def save(filename)
      assert_exists
      image_reader = @object.getImageReader
      file = java.io.File.new(filename)
      buffered_image = image_reader.read(0);
      javax.imageio.ImageIO.write(buffered_image, image_reader.getFormatName(), file);
    end
def save(filename)
      assert_exists
      image_reader = @object.getImageReader
      file = java.io.File.new(filename)
      buffered_image = image_reader.read(0);
      javax.imageio.ImageIO.write(buffered_image, image_reader.getFormatName(), file);
    end
Saves the image to the given file