Color verification apparatus, color verification system, and computer-readable storage medium storing a program

A color verification system comprising:

• a color measuring instrument having a color measuring aperture formed;
• and
• a color verification apparatus that performs color verification on a color verification target object based on a color measurement result from the color measuring instrument,
• wherein the color verification apparatus includes:
• an input processor that accepts input of a RIP image in a device-dependent color system and a color profile on condition that the RIP image is generated by performing rasterization and color conversion on an original document image including a color verification target object for image formation in an image forming apparatus and the color profile defines correspondence relationship between a color space based on a device-dependent color system for the RIP image and a color space based on a device-independent color system;
• a color measurement availability determiner that compares the color verification target object with a color measuring aperture of the color measuring instrument and determines whether the color measuring instrument can perform color measurement on the color verification target object, based on a comparison result indicative whether the color verification target object completely covers a color measuring aperture of the color measuring instrument;
• an estimation object list generator that extracts an estimation object and generates a list on condition that the estimation object is comparable to an object belonging to objects included in the RIP image, maintains uniform device-dependent color values of constituent pixels, and completely covers a color measuring aperture of the color measuring instrument;
• a theoretical color value acquirer that acquires a device-dependent color value of each pixel in the RIP image, uses the color profile to convert the device-dependent color value into a device-independent color value, and acquires the device-independent color value as a theoretical color value;
• a conversion coefficient calculator that calculates a conversion coefficient in order to derive a theoretical color value of the color verification target object from a theoretical color value of the estimation object acquired by the theoretical color value acquirer;
• a measured color value acquirer that measures the estimation object in a printed matter including the RIP image formed by the image forming apparatus by using the color measuring instrument and acquires a measured color value of the estimation object;
• an estimated color value calculator that calculates an estimated color value of the color verification target object from a measured color value of the estimation object and the conversion coefficient;
• and
• a color verifier that performs color verification on the color verification target object in the printed matter based on an estimated color value of the color verification target object calculated by the estimated color value calculator and a theoretical color value of the color verification target object acquired by the theoretical color value acquirer when the color measurement availability determiner produces a determination result indicative that color measurement is unavailable to the color verification target object.

A computer-readable storage medium storing a program to perform:

• an input processing procedure that accepts input of a RIP image in a device-dependent color system and a color profile on condition that the RIP image is generated by performing rasterization and color conversion on an original document image including a color verification target object for image formation in an image forming apparatus and the color profile defines correspondence relationship between a color space based on a device-dependent color system for the RIP image and a color space based on a device-independent color system;
• a color measurement availability determination procedure that compares the color verification target object with a color measuring aperture of a color measuring instrument and determines whether the color measuring instrument can perform color measurement on the color verification target object, based on a comparison result indicative whether the color verification target object completely covers a color measuring aperture of the color measuring instrument;
• an estimation object list generation procedure that extracts an estimation object and generates a list on condition that the estimation object is comparable to an object belonging to objects included in the RIP image, maintains uniform device-dependent color values of constituent pixels, and completely covers a color measuring aperture of the color measuring instrument;
• a theoretical color value acquisition procedure that acquires a device-dependent color value of each pixel in the RIP image, uses the color profile to convert the device-dependent color value into a device-independent color value, and acquires the device-independent color value as a theoretical color value;
• a conversion coefficient calculation procedure that calculates a conversion coefficient in order to derive a theoretical color value of the color verification target object from a theoretical color value of the estimation object acquired by the theoretical color value acquisition procedure;
• a measured color value acquisition procedure that measures the estimation object in a printed matter including the RIP image formed by the image forming apparatus by using the color measuring instrument and acquires a measured color value of the estimation object;
• an estimated color value calculation procedure that calculates an estimated color value of the color verification target object from a measured color value of the estimation object and the conversion coefficient;
• and
• a color verification procedure that performs color verification on the color verification target object in the printed matter based on an estimated color value of the color verification target object calculated by the estimated color value calculation procedure and a theoretical color value of the color verification target object acquired by the theoretical color value acquisition procedure when the color measurement availability determination procedure produces a determination result indicative that color measurement is unavailable to the color verification target object.