Abstract: Background subtraction methods have been used to obtain human silhouettes for gesture and gait recognition. However, background subtraction in pixel units is prone to error which decreases recognition performance significantly. In this paper we propose a novel background subtraction method that extracts foreground objects in region units. Together with the background model, an object's color and movement information are used to obtain the effective region object likelihood. Then an adaptive region decision function determines the object regions. Also, the sequential version of Horprasert's algorithm[2] is presented.