关键词: 机器视觉, 套色控制, 快速查找表, 行程长编码技术

Abstract: Automatic register control is the core of the whole printers’ control system，it is the key factor for deciding the printing precision.In this paper，a machine vision based register control system is designed to be used in chromatic printing machine.Firstly，the image of color marks is obtained by CCD（Charge Coupled Device）.A Fast Look-Up-Table（FLUT） is established in order to confirm the scope of RGB values of the color mark.The Run Length Encoding（RLE） technique is applied to reconstruct the image and calculate the center of gravity of the color mark.At last，it is compared with the standard position to show whether the registration deviation is exist or not.Experiment proves that it only takes few microseconds to detect twelve colors at once，which is suit to high speed chromatic printing machine.

Key words: machine vision, register control, Fast Look-Up-Table（FLUT）, Run Length Encoding（RLE）