1. An imaging device comprising: a taking lens having a plurality of regions, the plurality of regions each with an independent characteristic; an image pickup element having a plurality of light-receiving sensors provided so as to correspond to the plurality or regions, the plurality of light-receiving sensors performing pupil division of a light beam passing through any of the plurality of regions for selective light-receiving; an image generating unit which generates, from an imaging signal from a light-receiving sensor corresponding to one region of the plurality of regions, an image corresponding to the one region; and an image correcting unit which corrects the generated image, wherein the characteristic is at least either one of a focal length and a focal distance, and the image correcting unit removes an influence of a light beam passing through a region other than the one region from the image generated so as to correspond to the one region.