A color chart for color selection to select a color patch of the closest color to a target color from among a plurality of the color patches, in which the color patch that represents colors of either an adjustment target color or a reference color that substitutes the adjustment target color is a target patch, a direction that represents a direction in which a color is to be adjusted from the target patch in the color chart for color selection is an adjustment direction, and the adjustment direction from the target patch is wider than the direction counter to the adjustment direction from the target patch.

An image forming apparatus performs printing of only a special color area by extracting an area to which a special color ink is to be applied or an area to which a decorative printing, such as a texture, is to be performed and not applying ink on an area other than the extracted area.

A calibration system includes an image forming apparatus, a color-measurement device, a primary-color-input-output-characteristics adjustment unit, and a secondary-color-input-output-characteristics adjustment unit. The primary-color-input-output-characteristics adjustment unit adjusts input-output characteristics of a primary color of the image forming apparatus by correcting a gamma correction table for the primary color. The secondary-color-input-output-characteristics adjustment unit adjusts input-output characteristics of a secondary color of the image forming apparatus by correcting the gamma correction table for the primary color using the measurement results of the chart for the secondary color. The chart for the secondary color is printed by the image forming apparatus after the adjustment. The secondary-color-input-output-characteristics adjustment unit, as a combination ratio of two color materials, obtains the combination ratio where a hue angle of the specific secondary color becomes a defined hue angle so as to correct the gamma correction table for the primary color corresponding to the obtained combination ratio.

According to exemplary methods, a processor of a printing device determines color values out of a first colorant combination using marking materials for standard colorants and marking materials for one or more extended gamut colors. The extended gamut color has colorants other than the standard colorants. Responsive to the first colorant combination including color values for each of a pair of two complementary colors, the processor calculates a second colorant combination that produces the same human-perceivable color as the first colorant combination. The second colorant combination includes only one color of the pair of two complementary colors. The printing device produces output using the second colorant combination for the standard colorants and the extended gamut color.

Methods for configuring and calibrating a printing system are described. Configuring a printing system involves obtaining data for determining a reference print element in the printing system. The reference print element is then used to determine calibration data for a given print element. The calibration data is applied for the given print element to generate a print output.

A print color management apparatus includes a table control section that creates a first table; a registering section that causes each image forming apparatus to register a specific print color assigned to itself and a name of the specific print color; and a chart data creating section that creates print data of a chart. In the print data, color values are specified for color patches for print color management and color name is specified for a first specific patch on the basis of the first table. The print color management apparatus further includes a chart judging section that obtains measured color data of a chart printed, and judges, on the basis of the measured color data, whether the measured chart is usable for print color management of a designated image forming apparatus; and a print color management section that performs the print color management according to the judgement result.

The disclosure relates to a method for color correcting a digital printer over a printing width of the digital printer, having the steps of: a) providing a specified digital image, said digital image having at least one color channel pattern, wherein each color channel pattern is assigned to a print color channel of the digital printer; b) determining at least one test color of the specified digital image; c) generating a digital test pattern, said digital test pattern being provided with at least one single-colored test strip which is designed to be printed over the printing width of the digital printer, d) printing the digital test pattern using the digital printer; e) detecting the color values of the printed test pattern on the basis of the position thereof in the direction of the printing width using an optical color measuring device; f) generating correction data for the digital printer using the detected color values; and g) using the correction data on the digital printer and/or the specified digital image. The method is suitable in particular for color correcting substantially single-colored prints and for reducing the formation of stripes in the printing direction.

According to exemplary methods, a processor of a printing device determines color values out of a first colorant combination using marking materials for standard colorants and marking materials for one or more extended gamut colors. The extended gamut color has colorants other than the standard colorants. Responsive to the first colorant combination including color values for each of a pair of two complementary colors, the processor calculates a second colorant combination that produces the same human-perceivable color as the first colorant combination. The second colorant combination includes only one color of the pair of two complementary colors. The printing device produces output using the second colorant combination for the standard colorants and the extended gamut color.

There are provided a printing system, a method of generating a halftone processing rule, a method of acquiring a characteristic parameter, image processing device and method, a halftone processing rule, a halftone image, a method of manufacturing a printed material, an ink jet printing system, and a program which are capable of reducing an operation load of a user and acquiring a halftone processing rule appropriate for the printing system. A characteristic parameter acquisition chart (100) including a pattern for acquiring characteristic parameters related to characteristics of the printing system is output, and the output characteristic parameter acquisition chart (100) is read by image reading means. The characteristic parameters are acquired by analyzing the read image of the characteristic parameter acquisition chart (100), and halftone processing rules that define the processing contents of halftone processes used in the printing system are generated based on the acquired characteristic parameters.

The present disclosure advantageously provides apparatus, systems and methods which facilitate estimating and accounting for illumination conditions, viewing conditions and reflectance characteristics for imaged surfaces when performing color measurement, correction and/or transformation in an imaging process, such as photography. Advantageously, the disclosed apparatus, systems and methods may utilize a set of one or more illumination target elements for extrapolating illumination conditions from an imaged scene. The disclosure may be used to improve determination of color correction/transformation parameters and/or to facilitate determining a reflectance model for a target surface of interest.