Figure 3.

Diagram showing the whole configuration of the CUN face database. To capture face images with varying poses, expressions, accessories, and lighting conditions, a special photographic room with the dimension of 8.0 m length, 8.0 m width and 3.5 m height is set in our laboratory, and the necessary apparatuses are configured in the room including a multicamera system, a lighting system and control device, accessories, and various backgrounds. Note that in an effort to simulate the ambient illumination, two photographic sunlamps of high power covered with a ground glass are used to irradiate to the rough white ceiling, which can obtain more uniform lighting and mimic the normal outdoor-lighting environment (overhead lighting sources). To generate various directional lighting conditions needed, we set up a lighting system of 15 fluorescent lamps in the photographic room using multiple lamps and lamps hades, in a semicircle configuration [22].