# File lib/rqrcode/qrcode/qr_util.rb, line 257
    def QRUtil.demerit_points_4_dark_ratio(modules)
      # level 4
      dark_count = modules.reduce(0) do |sum, col|
         sum + col.count(true)
      end

      ratio = dark_count / (modules.size * modules.size)
      ratio_delta = (100 * ratio - 50).abs / 5

      demerit_points = ratio_delta * DEMERIT_POINTS_4
      return demerit_points
    end