1. A depth image based 3-dimensional (3D) object representing apparatus comprising: a viewpoint information generator for generating at least one piece of viewpoint information; a first image generator for generating color images on the basis of color information corresponding to the viewpoint information on the respective pixel points constituting an object; a second image generator for generating depth images on the basis of depth information corresponding to the viewpoint information on the respective pixel points constituting an object; a node generator for generating image nodes composed of viewpoint information, a color image and a depth image corresponding to the viewpoint information; and an encoder for encoding the generated image nodes.