Colorimetric value acquisition method, image forming device, and colorimetric value acquisition control program

An image forming device provided with a printing unit, an in-line scanner configured to acquire an RGB value by measuring an image formed by the printing unit, and an in-line colorimetric unit configured to acquire a colorimetric value formed of an L*a*b* value or an XYZ value by measuring an image formed by the printing unit, comprising:

• a profile creating unit configured to cause the printing unit to print a first chart in which patches are rearranged in advance such that a flare level is uniform, to cause the in-line scanner to measure all the patches of the first chart to acquire RGB values, to cause the in-line colorimetric unit to measure all the patches to acquire colorimetric values, and to create a scanner profile by correlating the RGB values with the colorimetric values;
• a correction amount calculating unit configured to cause the printing unit to print a second chart in which patches are rearranged in advance such that a flare level is uniform, to cause the in-line scanner to measure all the patches of the second chart to acquire RGB values, to cause the in-line colorimetric unit to measure a part of the patches to acquire colorimetric values, to specify an RGB value corresponding to each of the acquired colorimetric values using the scanner profile, and to calculate a difference between the RGB value specified using the scanner profile and an RGB value of each of the part of the patches acquired by measurement with the in-line scanner;
• and
• a colorimetric value estimating unit configured to calculate a corrected RGB value by applying the difference to an RGB value of each of the patches acquired by measurement with the in-line scanner, to acquire an estimated colorimetric value corresponding to the corrected RGB value using the scanner profile, and to output the estimated colorimetric value for color management of the image forming device.

A non-transitory recording medium storing a computer readable program configured to control acquisition of a colorimetric value, operated by a system including an image forming device provided with a printing unit, an in-line scanner configured to acquire an RGB value by measuring an image formed by the printing unit, and an in-line colorimetric unit configured to acquire a colorimetric value formed of an L*a*b* value or an XYZ value by measuring an image formed by the printing unit, wherein the program causes a control device in the system to execute:

• first processing configured to cause the printing unit to print a first chart in which patches are rearranged in advance such that a flare level is uniform, to cause the in-line scanner to measure all the patches of the first chart to acquire RGB values, to cause the in-line colorimetric unit to measure all the patches to acquire colorimetric values, and to create a scanner profile by correlating the RGB values with the colorimetric values;
• second processing configured to cause the printing unit to print a second chart in which patches are rearranged in advance such that a flare level is uniform, to cause the in-line scanner to measure all the patches of the second chart to acquire RGB values, and to cause the in-line colorimetric unit to measure a part of the patches to acquire colorimetric values;
• third processing configured to specify an RGB value corresponding to each of the colorimetric values acquired in the second processing using the scanner profile;
• fourth processing configured to calculate a difference between the RGB value specified in the third processing and an RGB value of each of the part of the patches acquired in the second processing;
• fifth processing configured to calculate a corrected RGB value by applying the difference to an RGB value of each of the patches acquired in the second processing;
• and
• sixth processing configured to acquire an estimated colorimetric value corresponding to the corrected RGB value using the scanner profile, and to output the estimated colorimetric value for color management of the image forming device.