双重识别功能的印刷套印标记设计及误差分析

Design of Overprint Marks with Double Discriminating Function and Analysis of Deviation

在传统的十字线套印标记和圆形套印标记基础上,设计了一种既适于人眼识别又适合数字图像检测的套印标记。利用CCD成像,获取了套印标记图像,然后对图像进行了预处理,分割图像,获取了同心圆中四色的圆心坐标,最后计算了套印偏差参数。实验结果表明:套印标记中的同心圆的设计,避免了图像分割时四色重叠的问题;套印偏差识别精度高,在分辨率达到300dpi及以上时,测量误差小于0.04mm,且识别速度快,能满足套印标记实时检测要求。

A novel overprint marks suitable for both human eyes and digital images was designed based on conventional cross registering mark and registering circle marks.The images of the register marks were collected by CCD components.The images were pretreated and segmented.The coordinates of the four colors circle centre and the parameters for overprint deviation were determined after digital image processing and image segmentation.The results showed that the homocentric circles in register marks can avoid overlapping between four colors in image segmentation;the method possesses much higher precision with overprint deviation less than 0.04 mm in case of image resolution above 300 dpi.Meantime,it owns fast recognition,which can satisfy the requirement of detecting overprint marks on line.