Machine vision detection method based on four-colour printed matter registration detection marks

Abstract

The invention discloses a machine vision detection method based on four-colour printed matter registration detection marks, comprising the following steps of: presetting graphs of the four-colour printed matter registration detection marks, and taking the circle centre of a black solid circular mark graph as a reference of the registration detection marks, wherein the circle centre of a yellow annular mark graph, the circle centre of a pinkish red annular mark graph, and the circle centre of a cyan annular mark graph are respectively as same as the circle centre of the black solid circular mark graph; acquiring images of preset graphs of the registration detection marks during a printing process; respectively obtaining coordinates of the circle centres of the registration detection marks in the images by a computer system; calculating registration deviation via the coordinates of the circle centres; comparing the squared value of the registration deviation with a deviation tolerance level; and finally, outputting a registration deviation result. The registration detection marks are simple in structure and small in occupied space, and camera can be convenient to rapidly and accurately shoot. According to the corresponding detection method, only deviation analysis does need to be performed via circle centre parameters, thus being high in detection efficiency, intuitive in result, and capable of realizing online detection for high-speed printed matters.

Description

technical field [0001] The present invention relates to a machine vision detection method based on four-color print registration detection marks, in particular to a machine vision detection method using four-color print registration detection marks and corresponding four-color print registration detection marks . Background technique [0002] In the color printing process, four colors of Y (yellow), M (magenta), C (cyan), and BL (black) are often used for printing. After printing, the staff adjusts the registration mechanism by estimating the deviation of the registration detection mark near the edge of the printed product. Finally, it is hoped that the four colors will overlap as much as possible so that the printed product can achieve the best clarity. Registration detection marks and corresponding detection methods are key links in four-color printing technology. [0003] The registration detection of traditional color prints is through manual visual inspection. The ope...

AI Technical Summary

Problems solved by technology

[0003]The traditional registration inspection of color prints is through manual visual inspection. The deviation between the cyan mark and the black mark, the disadvantages of the registration detection of the above-mentioned traditional color prints are: 1. The registration speed is slow and the efficiency is low; 2. The detection quality is unstable

However, this method does not explain the registration detection marks, and many registration detection marks on the market, such as linear registration detection marks, occupy a large sp

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