A Vision System with Dual Viewing Angles for Spontaneous Speech Dialogue Environment

This paper describes a vision system with dual viewing angles, i.e., wide and narrow viewing angles, and a scheme of user-friendly speech dialogue environment based on this vision system. The wide viewing angle provides a wide viewing field for wide range motion tracking, and the narrow viewing angle is capable of following a target in wide viewing field to take the image of the target with a sufficient resolution. For a fast and robust motion tracking, we define a modified motion energy (MME) and a existence energy (EE) for detecting the motion of the target and extracting the motion region at the same time. Instead of using a physical device such as a foot switch, the beginlend of user's utterance are determined by detecting the movement of mouth.