Research on a New Technique of No Mark Overprint
There are some problems with traditional mark replacement and accurate detection of overprint deviation, this paper presents a new method which can detect the parameter of the no mark overprint. The method is based on the basis of mathematical morphology to determine the sign of the multi-structural elements and multi-scale morphological edge, by using detection algorithm to extract image edge; and then the image edge was fitted by using least square fitting algorithm, so the sub-pixel center coordinates of the overprint mark can be obtained; Finally, accurate data of the overprint deviation can be obtained by using deviation operation formula. Theoretical analysis and experimental results show that the overprint deviation detection has high precision, which can help to improve the accuracy, real-time and automatic control of overprint. So it can ensure that the whole picture's tone and hue of printing image can be reproduced accurately.
Y. Wang et al., "Research on a New Technique of No Mark Overprint", Advanced Materials Research, Vols. 314-316, pp. 2512-2517, 2011