1. An outputting apparatus for outputting an image, the apparatus comprising: a color image obtaining unit configured to obtain a color image having multiple colors; a first monochrome image generating unit configured to generate a plurality of monochrome images by applying a plurality of mutually different calculations to the color image; a contrast calculating unit configured to calculate respective contrasts for the plurality of monochrome images; and an outputting unit configured to output a monochrome image derived from one of the calculated contrasts which satisfies a predetermined condition.