Zoom tracking for big magnification surveillance

In order to ensure the image clarity of the high-definition surveillance cameras in the large-range zooming process, a new zoom tracking method was presented. In this method, confidence interval was constructed by geometric method according to several zoom trace curves which were collected in advance; Zoom tracking curve was determined by the center position of confidence interval, and its dynamically adjusted with the adaptively adjusted confidence interval. This method was realized in an 18 digital high-definition surveillance camera. Experimental results indicate that the average bias of the focus motors position relative to its best position is less than 0.018 75 mm and the average time of zooming from wide-angle to tel-angle is 4.1 s.