Face recognition provides an important means for realizing a man-machine interface and security. This paper presents "Smartface," a PC-based face recognition system using a temporal image sequence. The face recognition engine of the system employs a robust facial parts detection method and a pattern recognition algorithm which is stable against variations of facial pose and expression. The functions of Smartface include (i) screensaver with face recognition, (ii) customization of PC environment, and (iii) real-time disguising, an entertainment application. The system is operable on a portable PC with a camera and is implemented only with software; no image processing hardware is required.