Methods and apparatus provide, for each partial area into which a display area is divided, determining multiple pixel groups including pixels overlapping a two-dimensional area; allocating the pixels belonging to the multiple pixel groups to any one of multiple processing groups that are each capable of including pixels whose number is smaller than or equal to a predetermined parallel number; calculating in parallel each color of pixels belonging to the processing group on the basis of the color calculation information stored in the memory; and outputting image data on the basis of the calculated color.