Embodiments of the present disclosure provide an image calibration method, an image forming apparatus, and a storage medium. The method includes outputting a calibration image in response to a calibration instruction, where the calibration image includes a calibration pattern and a calibration mark; according to the calibration mark of the calibration image, determining whether a calibration event corresponding to the calibration image matches a calibration event corresponding to a current calibration operation, or determining whether a calibration event type corresponding to the calibration image matches a calibration event type corresponding to a current calibration operation; and performing image calibration according to the calibration pattern in the calibration image if the calibration event corresponding to the calibration image matches the calibration event corresponding to the current calibration operation, or if the calibration event type corresponding to the calibration image matches the calibration event type corresponding to the current calibration operation.

A method of operating a printer separates the image data content of a sheet in a print job into multiple color separations. The first color separation printed on the sheet includes at least two fiducials printed in the least perceptible color of ink in the printer. The at least two fiducials are used to identify the process direction and skew of the printed sheet before the remaining color separations are printed on the sheet with the first color separation.

There is provided a printing apparatus including an obtaining unit configured to obtain print data in which in imposition image data in which one or more images are imposed in a print region, a code for identifying each image in the imposition image data is embedded; a determination unit configured to determine an ink color to be used to print the code by excluding an ink color satisfying a predetermined condition from candidates for the ink color to be used to print the code; and a print control unit configured to print the code based on the print data obtained by the obtaining unit using a plurality of nozzle arrays for the ink color determined by the determination unit.

Provided is an image processing method for generating print data, the method including an ink amount generating step for generating CMYK data based on image data. The ink amount generating step determines the CMYK data based on a brightness L* calculated using a function f3(D) satisfying f1(D)≥f3(D) in a range of the gradation values D from a coordinates Pk to a coordinates Ps and also satisfying f1(D)≥f3(D) in at least part of the range.

A color printing system manages ICC profiles by controlling ink use without performing the ICC profile creation operations. To obtain an ink limit for an ICC profile, a table associated with the ICC profile is parsed to determine the ink limit. The ink limit is decreased or increased. For an ink limit decrease, a color over the decreased ink limit is adjusted to meet the new ink limit. The ICC profile is updated accordingly. For an ink limit increase, the combination of primary colors are boosted by a percentage amount. Checks are made with regard to the volume-based ink limit and an quality check operation to accepted the boosted amount. The ICC profile is updated accordingly.

An image processing apparatus comprises a generation unit configured to generate correction information for reducing density change in image formation using a printing material including a plurality of colors. The generation unit generates correction information, sequentially in ascending order from a region of a smaller number of printing materials in a read-out image acquired by reading an image formed using a printing material including a plurality of colors, the correction information corresponding to a printing material for which correction information has not been generated among the printing materials used for the region.

An image forming apparatus includes a memory and circuitry. The memory stores a colorimetric value of a gradation correction chart and environmental information each time of acquisition of the colorimetric value. The circuitry predicts an output characteristic of an image formed by the image forming apparatus based on the colorimetric value associated with particular environmental information among the environmental information stored in the memory, the particular environmental information being within a predetermined range with reference to current environmental information, when the image forming apparatus is to output the gradation correction chart. The circuitry adjusts the output characteristic of the image in a case that the predicted output characteristic is lower than a target output characteristic. The circuitry corrects a gradation correction table based on the colorimetric value of the gradation correction chart and the target output characteristic.

An information processing apparatus includes: circuitry that converts: a total-amount restriction value that is input into a value corresponding to a gradation value; for each of colors of color materials included in an image forming apparatus, convert a gradation value of color information into a value of a color material amount normalized using a gradation value of the color of the color information; perform total-amount restriction on the normalized and converted value of the color material amount of the each of the colors based on the converted value corresponding to the gradation value; and convert the value of the color material amount of the each of the colors after the total-amount restriction into the gradation value of the each of the colors.

A printing system includes an offline estimation device that provides estimates for ink or toner use for a print job at a target printing device. The offline estimation device retrieves digital front end (DFE) version information, configuration setting information, and color printing resources from the target printing device. Using the DFE version information, the offline estimation device selects a raster image processor (RIP) from a plurality of RIPs of software versions available within the printing system. The offline estimation device configures the RIP with configuration settings of the configuration setting information. The color printing resources also are pushed to the RIP. The offline estimation device provides the ink or toner use estimate using the configured RIP.

A non-transitory computer-readable medium stores computer-readable instructions. The instructions instruct a computer to perform processes including an acquisition step, a determination step, and a display step. The acquisition step includes acquiring a specified color. The determination step includes determining whether a device-independent color based on the specified color is present within a first color gamut based on first print settings of a printer. The display step includes displaying, when it is determined by the determination step that the device-independent color is present within the first color gamut, second print settings of the printer. The second print settings are different from the first print settings and with which the device-independent color is present within a second color gamut that is based on the second print settings.