Most vision systems are currently task-oriented, which means that different systems are configured for different vision tasks in various environments. Anyway, a good vision system should make full use of all the merits of each component within the system. The main objective of this chapter is to provide a brief introduction of various components involved in the concerned vision system, i.e. structured light system and omni-directional vision system. And their characteristics are analyzed at the same time. Firstly, we introduce the mathematical models for the mirror, the camera and the projector, respectively. Then the coding and decoding strategies for the light pattern of the projector are discussed. Finally, we present some preliminaries that will be used in the succeeding chapters.