1. An image processing apparatus comprising: a multi-layer processing unit to classify an inputted depth image into a foreground layer, a middle layer, and a background layer; a representative color calculator to calculate a representative color of each of the classified layers; a color stereoscopy modeling unit to perform rendering of a color stereoscopy of the middle layer and a color stereoscopy of the background layer based on the representative color and a lightness of the background layer; a color temperature processing unit to control a color temperature of the foreground layer and a color temperature of the middle layer based on the representative color and the lightness of the background layer; and a rendering image unit to output a three-dimensional image using the image rendered by the color stereoscopy modeling unit.