Offset printing spot color ink computer color matching method, device and system and medium

Abstract

The invention discloses an offset printing spot color ink computer color matching method, device and system and a medium. The method comprises the following steps: proofing basic ink for color matching according to a preset concentration gradient, and constructing a database; measuring the gradient proofing sample to obtain the spectral reflectivity of the proofing sample and the spectral reflectivity of the proofing base material; measuring the target sample to obtain the spectral reflectivity of the target sample; then establishing a basic color matching model based on the spectrum matching degree of the proofing sample and the target sample, and obtaining a formula with the minimum spectrum difference as an initial formula; sampling according to the initial formula to obtain an initial formula spline, judging whether the color difference between the initial formula spline and the target sample is within a preset range or not, and if so, determining the initial formula as a final formula; otherwise, according to the initial formula spline, performing formula correction of the minimum constraint condition of the chromatic aberration until the chromatic aberration of the final corrected formula spline and the target sample is within the preset range, obtaining a more accurate formula, and improving the accuracy of target color restoration.

Description

technical field [0001] The invention relates to the field of printing technology, in particular to a computer color matching method, device, system and medium for offset printing spot color ink. Background technique [0002] In the printing industry, due to the limited printing color gamut of the traditional basic ink of yellow, magenta, cyan, and black (in actual use, some companies also call it yellow, red, blue, and ink), it cannot satisfy people's requirements for color. effect needs. In order to obtain special surface color effects for printed matter, the printing industry has long used spot color printing to widen the color gamut so that printing can present more colors. [0003] The so-called spot color refers to the color that cannot be presented by superposition of traditional four-color ink dots, that is, the color beyond the traditional four-color printing color gamut. With the continuous development of industrial Internet technology, customers in the printing i...

AI Technical Summary

Problems solved by technology

[0004] So far, most applications and researches have used the traditional K-M theoretical formula as the core formula for translucent material mixing: some use the minimum color difference as a constraint condition, but this method is prone to cause metamerism, and under different lighting conditions There are obvious color differences under human eye observation; some use the minimum spectral difference as a constraint condition, but the accuracy of color matching is often not accurate enough, resulting in a large color difference; The result of the smallest color difference and spectral difference, but the final result of this method is only between the first two methods after practical application

And, more importantly, most of the existing offset printing spot color ink matching methods lack a correction algorithm that is reasonably suitable for offset printing inks, but use the same correction algorithms in the textile and other fields, such as Sanderson correction, tristimulus value XYZ Correction, but these correction algorithms are not the best choice in the actual offset printing ink color matching process

[0005] The existing computer spot color automatic color matching technology cannot meet the practicality, standardization and rationality due to ignoring the influence of the base material in the field of offset printing ink and the error between the theoretical prediction result and the actual proofing result

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