1. An image processing apparatus comprising: an image selection means for selectively extracting one image data from a plurality of input image data; an image generation means for generating a computer graphics image based on computer graphics description data; a surface designation means for designating a surface of a predetermined polygon using surfaces of polygons among the computer graphics description data as a selection; and an image mapping means for texture-mapping an image according to the image data extracted by the image selection means onto the surface of the predetermined polygon designated by the surface designation means.