Recently, the quality of 3-D virtual spaces has become an important issue in virtual reality research. In order to generate more photo realistic 3-D virtual spaces, methods based on two dimensional photo images should also be considered in addition to the approaches based on typical three dimensional models. In this paper, two approaches based on 2-D photo images are discussed in which 3-D spaces are represented by manipulating 2-D photo images without any detailed 3-D information.