全景扫描仪自动聚焦系统研究

Research on the automatic focusing system in panorama scanner

为了满足快速、大批量自动聚焦的要求,提出一种软件聚焦方法。通过对相机采集的图像进行处理,采用图像内存与传统评价函数相结合的聚焦算法,得到扫描平面上一系列多个点精准的焦点位置。为了加快扫描速度,提高系统效率,平面上其他点通过确定点的焦点位置建立焦点平面完成聚焦。考虑到检测芯片不可能是绝对平面,焦点平面的建立采用最小二乘法实现。通过实验证明,当选取6个点进行精确聚焦时,建立的焦点平面可以满足设备要求。

A method for software automatic focusing is proposed to meet the requirements of the fast and the large number of focusing. By processing on the CCD image acquired and using the focusing algorithm based on combining image memory and the traditional evaluation functions presented in this paper, a series of points which have accurate focus positions on the scanning plane are obtained . In order to speed up the scanning speed and improve the efficiency of the system, the others on the plane complete focus on the basis of the focal plane built relying on the focused point. Considering the detection chip may not be an absolute plane, the focal plane is established by least square method. Focal plane meets the requirements of the equipment which is built by selecting 6 points for precise focus, proved by experiments.