应用于大变倍监控摄像机的电动变焦跟踪

Zoom tracking for big magnification surveillance

为了保持数字高清监控摄像机在大倍率电动变焦过程中的图像清晰度水平,提出一种新的电动变焦跟踪方法。该方法根据事先采集的若干条变焦曲线,利用几何法构造置信区间。以置信区间为变焦跟踪曲线的中心位置并且自适应地调整置信区间的位置,从而动态地修正变焦跟踪曲线。在18×数字高清摄像机中实现了该方法,实验结果显示:变焦过程中对焦电机的调节位置相对于最佳位置的平均偏离水平不大于0.018 75mm;变焦全程时间平均为4.1s。

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 it's 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 motor's 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 4.1s.