Smooth control of continuous autofocus

For a video camera to continuously focus on a moving object in the autofocus process, accurate estimate of the in-focus lens position is required in order to avoid the so-called bouncing phenomenon that is resulted from back-and-forth lens movements around the in-focus lens position. In this paper, we present a novel continuous focus method that effectively improves the accuracy of in-focus lens position estimate for dynamic scenes by a Kalman filter and provides good user experience by a smooth control of the lens movements in the autofocus process. Experimental results are shown to demonstrate the performance of our method.