1. An image processing apparatus comprising: an input unit configured to input a plurality of digital image data obtained by a plurality of image capturing units, each image capturing unit comprising a lens and an image capturing sensor comprising a plurality of pixels, each pixel comprising a pixel aperture, wherein a pixel aperture characteristic of the pixel apertures of the pixels of at least one of the image capturing units differs from a pixel aperture characteristic of the pixel apertures of the pixels of the other image capturing units and the plurality of digital image data represent images of a same subject captured from a plurality of viewpoints; and a generation unit configured to synthesize the plurality of digital image data input by the input unit to generate developed image data, wherein the developed image data represents an image consisting of a greater number of pixels than each image represented by the digital image data obtained by the each image capturing unit, wherein each of the pixel apertures is smaller in size than a pixel of the plurality of pixels that comprises the pixel aperture, and the pixel aperture characteristics indicate at the least one of a pixel aperture size, a pixel aperture shape, or an imaging magnification of a subject, and wherein the pixel aperture characteristics are determined for the individual image capturing units such that the lowest frequency at which loss of signal of the synthesized image occurs is higher than the lowest frequency at which loss of signal of the images captured by the image capturing units occurs.