Abstract: A 2D image generation unit 13 that generates 2D image data according to a predetermined 2D conversion algorithm from 3D data, and an evaluation value calculation unit 14 that calculates an evaluation value representing similarity between the generated 2D image data and captured image data used as a correct image are included. By the 2D image generation unit 13 repeatedly executing generation of 2D image data from 3D data and learning the 2D conversion algorithm to optimize the evaluation value calculated each time for 2D image data using highly accurate captured image data as a correct image, it is possible to generate a highly accurate 2D image from a 3D model even when 3D data of a highly accurate 3D model is not used.