A Method for Determining the Density of Three Primary Colors in Printing

Abstract

The invention belongs to the technical field of quality control in the printing process, and particularly relates to a method for determining the printing three-primary color density. According to the method, a control strip with each ink area including a cyan color lump, a pinkish red color lump, a yellow color lump, a red color lump, a green color lump and a blue color lump is designed; after printing, the spectral reflectance of each color lump is detected, the tristimulus values of each color lump and the main density values of each cyan color lump, each pinkish red color lump and each yellow color lump are calculated, and the tristimulus values of the cyan color, the pinkish red color, the yellow color, the red color, the green color and the blue color and the relation of the main density values of the cyan color, the pinkish red color and the yellow color are subjected to fitting through the least square method; and for the cyan color, the pinkish red color and the yellow color, according to the function relation between the tristimulus values and the main density, the tristimulus values and the chromatic values of the cyan color, the pinkish red color, the yellow color, the red color, the green color and the blue color are cyclically calculated when the main density is changed from low to high, and the chromatic aberration between the chromatic values and the standard chromatic values is calculated. According to the method, only the spectral reflectance of the ink areas on one or more printing sheets needs to be detected in a scanning manner, the requirement for the number of samples is low, the most reasonable density is determined through program calculation, efficiency is high, and the requirement for the skills of users is low.

Description

technical field [0001] The invention belongs to the technical field of quality control in the printing process, and in particular relates to a method for determining the densities of three primary colors in printing. technical background [0002] For a given paper and ink combination, how much printing ink volume is the most reasonable question. The traditional method is to obtain printed sheets with different ink shades by adjusting the output ink volume during printing, and detect the relative contrast on different printed sheets. , the density of the printed sheet with the largest relative contrast is the best solid density to control the printing ink volume of cyan, magenta, yellow and black. The literature "Research on the Determination Method of Optimum Printing Parameters of Offset Printing Ink" (Journal of China Printing and Packaging Academic Conference in 2010, Jiang Wenyan, Wang Zhihong) by establishing the relationship curve between relative contrast and solid de...

AI Technical Summary

Problems solved by technology

However, when this method determines the optimal density of cyan, magenta, and yellow, it determines the density based on the chromaticity values ​​of the three primary colors of cyan, magenta, and yellow as close to the standard value as possible, and does not take into account the three primary colors of red, green, and blue. The secondary color also needs to be as close to the standard value as possible, and the chromaticity value of the secondary color will change with the density of the two basic colors forming the secondary color

When the chromaticity value of the primary color is as close as possible to the standard, the chromaticity value of the secondary color may deviate greatly from the standard, or the comprehensive color effect of the primary color and the secondary color is unreasonable

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