A system is disclosed. The system at least one physical memory device to store ink estimation logic and one or more processors coupled with the at least one physical memory device, to execute the ink estimation logic to receive a histogram for each of a plurality of color planes, receive uncalibrated ink deposition data for a printing system, perform a direct conversion of the uncalibrated ink deposition data to generate first calibrated ink deposition data and generate estimated ink usage data for each of the plurality of color planes based on the histograms and the first calibrated ink deposition data.

A computer-implemented method is provided for dosing ink in a digital printing device with multiple ink channels, when printing on a reflective substrate. A digital printing system configured with the method is also provided. Target color data of a target color to be printed on the reflective substrate is captured, including both color data and spectral reflectance data. The captured color data is processed with a printer model to output a preliminary dosing ratio for each ink channel. A digital opacity value for the target color is computed from the dosing ratio of each ink channel. A natural opacity value for the for the target color is computed from the captured spectral reflectance data, and a difference between the digital and natural opacity values is calculated. A predicted dosing ratio for each ink channel is obtained by interpolating the difference against an ink step of a diffuse ink component of the target color.

An image forming apparatus includes an image forming unit configured to form an image on an image bearing member based on an image forming condition; a transfer unit configured to transfer the image formed on the image bearing member onto a sheet; a first reading sensor configured to read a first image for adjustment which has been formed on the sheet; a second reading sensor configured to read a second image for adjustment which has been formed on the image bearing member; and a controller configured to: generate the image forming condition based on reading results of the first image for adjustment on a plurality of sheets, which are obtained by the first reading sensor; and generate the image forming condition based on a reading result of the second image for adjustment, which is obtained by the second reading sensor.

A plurality of test patterns are printed with different print conditions, the test patterns each being formed by two inks out of a plurality of inks and a reaction liquid and including a plurality of patterns among which ejection positions of the reaction liquid relative to ejection positions of the two inks are displaced by a predetermined amount at a time. The optical properties of the respective test patterns printed on the print medium are detected. A displacement amount of the relative ejection positions of the reaction liquid from the ejection positions of the plurality of inks is obtained based on the optical property of the test pattern in which an optical density difference between the patterns in the test pattern is greater than a predetermined value and which has an optical density of a lowest level among the optical properties of the test patterns detected.

A pagewide array (PWA) print bar of a printing device prints a calibration pattern on a print medium. The print bar is nominally perpendicular to a media advancement direction in which the print medium advances relative to the PWA print bar during printing. An image of the printed calibration pattern is optically scanned, and a skew angle by which the PWA print bar deviates from true perpendicular to the media advancement direction is calculated based on the optically scanned image. The printing device is calibrated to compensate for the calculated skew angle during subsequent printing.

An image processing apparatus according to the present invention includes an image forming unit configured to form an image, a measuring unit configured to measure the formed image, a control unit configured to control execution of a single-color calibration to be performed to correct reproduction characteristics of a single-color formed by the image forming unit based on a measuring result of a single-color image formed with a single-color recording agent and execution of a multi-color calibration to be performed to correct reproduction characteristics of a multi-color image formed by the image forming unit based on a measuring result of a multi-color formed with a plurality of recording agents, and a selection unit configured to select whether to cause the control unit to perform the multi-color calibration after completing the single-color calibration or cause the control unit to perform any one of the single-color calibration and the multi-color calibration.

An inkjet image forming apparatus includes: an image former that forms an image on a transfer body by discharging an ink droplet from an inkjet head; and a hardware processor that detects a landing state of the ink droplet that has been discharged and landed on the transfer body and changes an image forming condition when the image is formed so that a detected landing state approaches a target landing state.

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.

A printing system is disclosed. The printing system includes at least one physical memory device to store uniformity compensation logic and one or more processors coupled with the at least one physical memory device to execute the uniformity compensation logic to receive print image measurement data corresponding with each of a plurality of pel forming elements, generate a first set of intermediate images based on the print image measurement data, determine whether historical sets of intermediate images are available, generate first transfer functions corresponding to each of the pel forming elements based on the first set of intermediate images and the historical sets of intermediate images upon a determination that the historical sets of intermediate images are available and transmit the first transfer functions for each of the pel forming elements.

A measuring device includes a first roller pair, a colorimetric unit, a second roller pair, a third roller pair, a motor, and a torque limiter. The third roller pair is driven at a first speed before a trailing end of the sheet with respect to a sheet feeding direction passes through the first roller pair and is driven at a second speed higher than the first speed after the trailing end of the sheet passes through the first roller pair. The first speed is set so as to be equal to the peripheral speed of the first roller pair. The second speed is set so as to be equal to a peripheral speed of the second roller pair in a state in which a slip of the torque limiter is not caused.