Color printing control using halftone control areas.

摘要

In a multi-color printing process, measurements of the optical density of two different three-color halftone control areas are used to calculate dot gain and solid density of the cyan, magenta and yellow images. Since no single-color solid control targets are used, control targets may be hidden or camouflaged in a border or logo in the final printed product. The two control targets can consist of light and dark near-neutral gray balance targets. Alternatively, two different three-color half-tone regions of the printed image can be used as control areas, eliminating the need for separate control targets. Densitometers having blue, green and red filters use the two three-color halftone control areas to provide density measurements which are used by a computer to calculate the densities of cyan, magenta and yellow halftone images. The computer then calculates the dot gain and solid density of the process inks, which are displayed to a pressman who can make appropriate adjustments to the printing process.