1. An apparatus for generating image data for reproducing material appearance of an object to be rendered on a printed material, the apparatus comprising: at least one processor; and a memory coupled to the at least one processor, the memory having stored thereon instructions which, when executed by the at least one processor cause the apparatus to: obtain a gloss level that evaluates glossiness of the object to be rendered; obtain a sparkle level of the object to be rendered, the sparkle level being a level of a property that changes positions of a plurality of luminous points depending on a position of a light source and an observation angle; and derive a parameter relating to use of a printing material 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.