1. A computer-implemented data conversion method comprising: rearranging, by a computer-implemented anisotropic texture converting unit, a plurality of texture images forming a multi-dimensional texture image in units of particular unit areas to convert the plurality of texture images into a plurality of anisotropic textures, wherein: each of the plurality of texture images is designated by parameters of a view position and parameters of a lighting position, each of the plurality of anisotropic textures expresses an anisotropic variation of the multi-dimensional texture image in a corresponding unit area, each of the anisotropic textures includes a plurality of block images; each of the plurality of block images is designated by parameters of a view position and parameters of lighting position of the corresponding unit area; and compressing, by a computer-implemented texture compressing unit, each of the anisotropic textures.