    # File lib/RMagick.rb, line 915
        def level(black_point=0.0, white_point=nil, gamma=nil)
            black_point = Float(black_point)

            white_point ||= Magick::QuantumRange - black_point
            white_point = Float(white_point)

            gamma_arg = gamma
            gamma ||= 1.0
            gamma = Float(gamma)

            if gamma.abs > 10.0 || white_point.abs <= 10.0 || white_point.abs < gamma.abs
                gamma, white_point = white_point, gamma
                unless gamma_arg
                    white_point = Magick::QuantumRange - black_point
                end
            end

            return level2(black_point, white_point, gamma)
        end