1. An image-processing apparatus for generating images from a plurality of viewpoints, comprising: a supplementation section that receives images captured by a plurality of image capturing devices arranged on a predetermined plane and generates supplemental images at a plurality of supplemental camera positions on the predetermined plane, each supplemental image being generated based on images captured by a predetermined number of the image capturing devices on the predetermined plane; and a viewpoint image generation section that generates a viewpoint image from a viewpoint by selecting pixels from the plurality of supplemental images and captured images.