1. An apparatus for generating image data for reproducing material appearance of an object to be rendered on a printed material, the apparatus comprising: a gloss level obtaining unit configured to obtain a gloss level that evaluates glossiness of the object to be rendered; a sparkle level obtaining unit configured to obtain a sparkle level that evaluates sense of sparkle of the object to be rendered; and a deriving unit configured to derive a parameter relating to use of ink for reproduction of the material appearance by an image forming device, the image forming device receiving and printing the image data based on the obtained gloss level and sparkle level.