A multi-modal system for tracking and analyzing faces on a mobile robot

This paper describes a user detection system which employs a saliency system working on an omnidirectional camera delivering a rough and fast estimate of the position of a potential user. It consists of a vision (skin color) and a sonar based component, which are combined to make the estimate more reliable. To make the skin color detection robust under varying illumination conditions, it is supplied with an automatic white balance algorithm. The active vision head looks continously in the direction of the salient region. Thus, a high resolution image can be grabbed and analyzed with a face detector.