A reliable algorithm for rendering depth of field (DoF) effects using estimated depth maps, obtained through stereo matching, is proposed in this paper. The proposed algorithm generates blurring to simulate images spontaneously seen by human vision systems. We develop two types of windows : circle of confusion (CoC) blurring window and peripheral blurring window. First, the CoC blurring window is determined by comparing the depth values of a gazing point and each sample point. Second, the peripheral blurring window is obtained by calculating the distance between the gazing and sample points. Then, we combine the two windows to make the total blurring window. Finally, through a masking process, we modulate the total blurring window to provide a more natural DoF. Experimental results demonstrate that the proposed algorithm provides realistic blurring, by preserving edges clearly as well as blurring far points from the gazing point effectively.