1. An image-capturing device, comprising: a photographic optical system; a photoelectric conversion element array made up with a plurality of photoelectric conversion elements, each of which receives a light flux having been transmitted through the photographic optical system and outputs a signal, arrayed therein; a micro-lens array disposed between the photographic optical system and the photoelectric conversion element array and made up with a plurality of micro-lenses arrayed therein, with the plurality of photoelectric conversion elements, arrayed at the photoelectric conversion element array, present behind each of the plurality of micro-lenses; a data creation unit that creates pixel data at a plurality of pixels on a specific image forming plane, at which an image is formed through the photographic optical system, in correspondence to each micro-lens among the plurality of micro-lenses by applying filter matrix data to output signals provided from the plurality of photoelectric conversion elements; and an image synthesis unit that synthetically generates an image on the specific image forming plane at a given position assumed along an optical axis of the photographic optical system, based upon the pixel data created by the data creation unit, wherein: the filter matrix data assume a two-dimensional data array pattern conforming to a specific intensity distribution with a distribution center thereof set at an element corresponding to a central position of a projection image of each of the plurality of pixels, projected on the photoelectric conversion element array via the each micro-lens among the plurality of micro-lenses.