Patent ID: 7755798
Filing Date: 2010-07-13
Classification: B41F,H04N

Abstract:
1. A picture color tone controlling method for a printing press, comprising: a noticed pixel region selection step of selecting a noticed pixel region to be noticed as an object of picture color tone control in a printing picture; a target color mixture halftone density setting step of setting a target color mixture halftone density regarding the noticed pixel region selected at the noticed pixel region selection step; an actual color mixture halftone density measurement step of measuring an actual color mixture halftone density for each noticed pixel region on an actually printed sheet obtained by printing using an IRGB densitometer; a target tone values arithmetic operation step of arithmetically operating target tone values of each ink color corresponding to the target color mixture halftone density based on a corresponding relationship between tone values and color mixture halftone densities set in advance; a changing ratio setting step of setting a changing ratio regarding the target tone values for each ink color; a target tone values changing step of changing the target tone values for each ink color arithmetically operated at the target tone values arithmetic operation step in response to the changing ratio set at the changing ratio setting step; an actual tone values arithmetic operation step of arithmetically operating actual tone values for each ink color corresponding to the actual color mixture halftone density based on the corresponding relationship between the tone values and the color mixture halftone densities; a target monochromatic halftone density arithmetic operation step of arithmetically operating a target monochromatic halftone density corresponding to the target tone values based on a corresponding relationship between tone values and monochromatic halftone densities set in advance; an actual monochromatic halftone density arithmetic operation step of arithmetically operating an actual monochromatic halftone density corresponding to the actual tone values based on the corresponding relationship between the tone values and the monochromatic halftone densities; a solid density difference arithmetic operation step of arithmetically operating a solid density difference corresponding to a difference between the target monochromatic halftone density and the actual monochromatic halftone density under the target tone values based on a corresponding relationship among tone values, monochromatic halftone densities and solid densities set in advance; and an ink supplying amount adjustment step of adjusting an ink supplying amount for each ink supplying unit width of an ink supplying apparatus based on the solid density difference.