1. An image synthesizing method, including: acquiring a two-dimensional image and a stereoscopic image that assumes a plurality of viewpoints and is constituted by background and an object; and replacing a pixel of the two-dimensional image by a pixel constituting the object where the pixel of the two-dimensional image is overlapped with the pixel constituting the object in the event that the acquired stereoscopic image is superposed on the acquired two-dimensional image, so as to produce stereovision on part of the two-dimensional image overlapped with the object.