def bgfill
      if @background_fill.nil?
        color = Magick::Pixel.new(0, 0, 0, Magick::TransparentOpacity)
      else
        color = @background_fill
        color.opacity = (1.0 - @background_fill_opacity) * Magick::TransparentOpacity
      end
      color
    end
def bgfill
      if @background_fill.nil?
        color = Magick::Pixel.new(0, 0, 0, Magick::TransparentOpacity)
      else
        color = @background_fill
        color.opacity = (1.0 - @background_fill_opacity) * Magick::TransparentOpacity
      end
      color
    end
background_fill defaults to 'none'. If background_fill has been set to something
 else, combine it with the background_fill_opacity.