Above all, the first step is about the choice to the pick-up camera used in digitizing image field and image card. Then we explore the structure feature and operating principle of expanding wheel of steel balls produced at SOMET in Czechoslovakia.

• 首先对图象数字化所用的摄像机和图象采集卡进行了选择,然后研究了捷克SOMET公司的钢球展开轮的结构特点和工作原理。