To make it possible to precisely and easily match printed color to the color tone desired by a printing requester or the like just after the start of printing with no need to wait until an OK sheet is printed with an IRGB densitometer, which is cheaper than a spectrometer.
By using the ICC profile of a scanning device and the device profile of an IRGB densitometer, target dot area percents are obtained from kcmy dot area percent data of the pattern of a printing object obtained from outside and a proof sheet. In addition, target monochromatic screen densities are obtained from these target dot area percents. After that, printing is started so as to obtain an actual compound color screen density of a printed running-on sheet with the IRGB densitometer. Actual monochromatic screen densities are obtained from the actual compound color screen density. Finally, a solid density deviation corresponding to the deviation between the target monochromatic screen density and the actual monochromatic screen density is obtained under the target dot area percent so as to adjust the amount of ink supply based on the obtained solid density deviation.
TAKEMOTO SHUICHI
TASAKA NORIBUMI
