Detection method of printed register

XV Haitao, HU Gengsheng

(Mechanical Engineering College, Hangzhou Dianzi University, Hangzhou 310018, China)

Abstract: In order to solve the problems of the accuracy about fourcolors overprint markers at online detection, the color image segmentation was investigated.The relationship between RGB and L*a*b* was established. The methods of threshold and ISODATA image segmentation were presented. The color image segmentation was realized by Matlab, and the accuracy of fourcolors overprint were evaluated. The experimental results show that the method can extract calculate the overprint error,and it can be used in the realtime printdetect system for Web offset printing.
Key words: digital image processing; overprint error; color space conversion; image segmentation