Image processing device, image forming system, image processing method, and non-transitory computer-readable storage medium

An image processing method comprising:

• obtaining a mixed spectral reflectance of a region in which a first color and a second color are mixed in an image including the first color and the second color, a plurality of first spectral reflectances of the first color, a plurality of first halftone dots associated with respective ones of the plurality of first spectral reflectances, a plurality of second spectral reflectances of the second color, and a plurality of second halftone dots associated with respective ones of the plurality of second spectral reflectances;
• determining a first wavelength range in which the plurality of first spectral reflectances are lower than the plurality of second spectral reflectances and a second wavelength range in which the plurality of first spectral reflectances are higher than the plurality of second spectral reflectances;
• estimating a first halftone dot associated with one first spectral reflectance, selected from the plurality of first spectral reflectances, in accordance with a matching rate with the mixed spectral reflectance in the first wavelength range, find a third spectral reflectance by dividing the mixed spectral reflectance by the first spectral reflectance selected, and estimate a second halftone dot associated with one second spectral reflectance, selected from the plurality of second spectral reflectances, in accordance with a matching rate with the third spectral reflectance in the second wavelength range;
• and
• correcting the first halftone dot and the second halftone dot of the first color and the second color, respectively, on the basis of a difference between a pre-set target for the first halftone dot and the second halftone dot and the first halftone dot and the second halftone dot estimated by the estimating, respectively.

A non-transitory computer-readable storage medium storing a program that, when executed by a computer, causes the computer to perform an image processing method, the non-transitory computer-readable storage medium comprising:

• obtaining a mixed spectral reflectance of a region in which a first color and a second color are mixed in an image including the first color and the second color, a plurality of first spectral reflectances of the first color, a plurality of first halftone dots associated with respective ones of the plurality of first spectral reflectances, a plurality of second spectral reflectances of the second color, and a plurality of second halftone dots associated with respective ones of the plurality of second spectral reflectances;
• determining a first wavelength range in which the plurality of first spectral reflectances are lower than the plurality of second spectral reflectances and a second wavelength range in which the plurality of first spectral reflectances are higher than the plurality of second spectral reflectances;
• estimating a first halftone dot associated with one first spectral reflectance, selected from the plurality of first spectral reflectances, in accordance with a matching rate with the mixed spectral reflectance in the first wavelength range, find a third spectral reflectance by dividing the mixed spectral reflectance by the first spectral reflectance selected, and estimate a second halftone dot associated with one second spectral reflectance, selected from the plurality of second spectral reflectances, in accordance with a matching rate with the third spectral reflectance in the second wavelength range;
• and
• correcting the first halftone dot and the second halftone dot of the first color and the second color, respectively, on the basis of a difference between a pre-set target for the first halftone dot and the second halftone dot and the first halftone dot and the second halftone dot estimated by the estimating, respectively.