1. An image-processing apparatus for generating images from a plurality of viewpoints, comprising circuitry configured to: receive images captured by a plurality of image capturing devices arranged on a predetermined plane and generate 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, the supplemental camera positions being different from positions of the image capturing devices; and generate a viewpoint image from a viewpoint based on a selection of pixels from the pixels of at least one of the supplemental images and captured images, wherein the viewpoint is selected from a focal area common to an imaging range of each of the plurality of the image capturing devices, and cause a display of the viewpoint image on a display device; wherein the circuitry is configured to calculate a deviation amount based on a parallax vector and a position vector, the deviation amount being used to determine a shift of an object in the viewpoint image, the parallax vector representing a movement of a same object in two images captured by two of the predetermined number of image capturing devices and the position vector representing the distance and position between the two image capturing devices.