1. An image reconstructing device comprising: an image information acquiring section that acquires information forming a lens array image, the lens array image is formed by a lens array comprising an array of sub-lenses including a first sub-lens and a second sub-lens for an optical image of an object formed by a main lens; an interpolating section that interpolates a third sub-image formed by a third sub-lens based on a first sub-image and a second sub-image constituting the lens array image, wherein the third sub-lens is positioned between the first sub-lens forming the first sub-image and the second sub-lens forming the second sub-image; a distance information acquiring section that acquires distance information indicating a distance to a point on which the main lens focuses; a reconstructing section that reconstructs an image of the object formed by the main lens focused on the point at the distance indicated by the acquired distance information from the interpolated third sub-image, the first sub-image and the second sub-image; and an image information outputting section that outputs information forming the reconstructed image.