An object of the present disclosure is to implement, at a low cost, highly accurate color calibration in a printing apparatus that performs printing using fluorescent ink. One embodiment of the present invention is an image processing apparatus that includes: a processing unit configured to perform processing relating to color calibration in a printing apparatus that prints an image on a printing medium using fluorescent printing material; and an execution unit configured to perform calibration processing of the printing apparatus based on a measured value that is obtained by measuring a patch chart for obtaining information on an amount of application of the fluorescent printing material in the printing apparatus, wherein a patch included in the patch chart is printed with the fluorescent printing material and subtractive color mixture printing material and at least one dot of the subtractive color mixture printing material covers a dot of the fluorescent printing material.

In an example, a method includes obtaining, by processing circuitry, a mapping from at least one measured color characteristic of a first substrate to at least one measured color characteristic of a second substrate, wherein the at least one measured color characteristic of the first substrate comprises a measured color characteristic of an unmarked portion of the first substrate and the at least one measured color characteristic of the second substrate comprises a measured color characteristic of an unmarked portion of the second substrate. In some examples the method further includes applying, by processing circuitry, the mapping to a first color which is obtained when applying at least one colorant according to a first colorant specification on the first substrate to determine a predicted color to be obtained by applying at least one colorant according to the first colorant specification on the second substrate.

An image forming apparatus includes: an image former that forms a correction patch using toner; a measurer that measures a color, a density, or a deposited amount of toner of the correction patch; and a hardware processor that calculates a reference correction amount on the basis of a measurement value of the measurer so that the density of the correction patch reaches a target value, and corrects an image forming condition of the image former by a first correction amount smaller than the reference correction amount.

A controller performs: acquiring target image data; calculating a particular value of a first end image by using the target image data, the first end image being an image to be printed in a first end region parallel to a first end of a print medium; determining print processing to be performed by using the particular value, including: when a particular condition is satisfied, determining first print processing as the print processing, the particular condition including a first condition that uniformity of the first end image is higher than or equal to a first standard; and when the particular condition is not satisfied, determining second print processing as the print processing, the first print processing being processing in which banding is less likely to occur in the first end image than the second print processing; and controlling the printer to print an image based on the target image data.

A color inspection device includes a reading device and circuitry. The reading device images a reference object and a color detection object to obtain readings of each of the reference object and the color detection object. The circuitry corrects the readings of the color detection object by using a correction coefficient that is generated from the readings of the reference object and color information measured for each arbitrary region of the reference object.

An image processing apparatus generates color conversion data in which first color component values in a first color space are associated with second color component values in a second color space. The apparatus executes determining a reference curve that takes a maximum value in the second color space among curves representing gradations of color components in the first color space; determining interpolation guide curves that represent a maximum gradation and a minimum gradation of a color component to be interpolated in the first color space; executing colorimetry on color patches corresponding to second color component values in the reference and interpolation guide curves; interpolating second color component values not included in the reference and interpolation guide curves, based on the second color component values obtained by the colorimetry; and generating the color conversion data by using the second color component values obtained by the colorimetry and the interpolation.

A color conversion LUT creation apparatus includes a derivation unit that derives an output value corresponding to a signal value in an input image for a plurality of virtual color materials whose number is smaller than a number of actual color materials used in an image forming apparatus; a setting unit that sets a target number of dots printed per unit area of the actual color material; and a conversion unit that converts an output value of the plurality of virtual color materials into an output value of the actual color material and creates a color conversion LUT in which the input value and the output value of the actual color material are associated with each other. The setting unit sets the target number of dots based on dispersibility of a dot pattern corresponding to each tone level of a dither matrix used for halftone processing.

An object of the present disclosure is to implement, at a low cost, highly accurate color calibration in a printing apparatus that performs printing using fluorescent ink. One embodiment of the present invention is an image processing apparatus that includes: a processing unit configured to perform processing relating to color calibration in a printing apparatus that prints an image on a printing medium using fluorescent printing material; and an execution unit configured to perform calibration processing of the printing apparatus based on a measured value that is obtained by measuring a patch chart for obtaining information on an amount of application of the fluorescent printing material in the printing apparatus, wherein a patch included in the patch chart is printed with the fluorescent printing material and subtractive color mixture printing material and at least one dot of the subtractive color mixture printing material covers a dot of the fluorescent printing material.

An image processing apparatus generates color conversion data in which first color component values in a first color space are associated with second color component values in a second color space. The apparatus executes determining a reference curve that takes a maximum value in the second color space among curves representing gradations of color components in the first color space; determining interpolation guide curves that represent a maximum gradation and a minimum gradation of a color component to be interpolated in the first color space; executing colorimetry on color patches corresponding to second color component values in the reference and interpolation guide curves; interpolating second color component values not included in the reference and interpolation guide curves, based on the second color component values obtained by the colorimetry; and generating the color conversion data by using the second color component values obtained by the colorimetry and the interpolation.

A controller performs: acquiring target image data; calculating a particular value of a first end image by using the target image data, the first end image being an image to be printed in a first end region parallel to a first end of a print medium; determining print processing to be performed by using the particular value, including: when a particular condition is satisfied, determining first print processing as the print processing, the particular condition including a first condition that uniformity of the first end image is higher than or equal to a first standard; and when the particular condition is not satisfied, determining second print processing as the print processing, the first print processing being processing in which banding is less likely to occur in the first end image than the second print processing; and controlling the printer to print an image based on the target image data.