This paper presents a system that can extract regions of a person from an image sequence. The system first detects foreground regions based on a background model. After foreground regions are extracted a human model is used to identify human regions. In the human model, we adopt a Hidden Markov Model (HMM) to model human silhouettes. To separate human and non-human regions, we represent non-human silhouettes by another HMM. The human silhouette model can extract incomplete human regions even when parts of the person are covered by background objects. Experimental results show the system proposed is very effective.