An approach to the tracking of trajectories of 3-D human motion from image sequence based on adaptive foreground segmentation and particle filter is proposed in this paper. First, the Gaussian model for image pixel is presented. Based on this, the adaptive segmentation of human body is finished using the information of difference image and the prior distribution of pixel density. Then, the tracking model under perspective imaging for body plane is established. Due to the fact that image function is nonlinea...