Provided is an image processing device used for image processing in an image forming device that executes linear image forming in a first direction repeatedly in a second direction orthogonal to the first direction and executes two-dimensional image forming on a recording medium, the image processing device including: a processor configured to: acquire a phase of a member that contributes to image forming by rotating or circulating in the second direction and calculate, for each of different phases, an input/output gradation characteristic indicating a correspondence relationship in density in the same pixels in pre-output image data and post-output image data acquired by scanning of an image formed on the recording medium; calculates correction data to solve a difference between the input/output gradation characteristic in each of the phases and a reference input/output gradation characteristic; and correct the pre-output image data with the correction data of each of the phases.

A redundantly printed security-enhanced document, printing method, and system for better ensuring that the meaning of the information imparted by variable indicia printed by redundant printing indicia on a document protected by a removable Scratch-Off Coating (SOC). By printing the variable indicia with multiple colors, redundancy and integrity of the intended indicia is achieved relative to the perception of human eye photoreceptor cones. The redundantly printed document, methods, and systems enhance the overall appearance of the redundantly printed document, and reduce possible consequences resulting from misprinted variable indicia.

A printing apparatus includes a control unit configured to execute image processing including a division and a combination of image data, and a printing unit configured to perform printing on a printing medium based on image data after the image processing, wherein the control unit acquires image data as a target of the n-th image processing, generates an upper image whose lower side is horizontal, and a lower image whose upper side is horizontal by dividing the image data by a horizontal line, generates combined image data whose upper side and lower side are horizontal by combining a lower image whose upper side is horizontal and that is generated by the division in the image processing at the (n−1)-th time, on the upper side of the upper image, and causes the printing unit to execute printing based on the combined image data.

An image forming apparatus includes an image forming unit to form an image on a sheet, a conveyance unit to convey the sheet having the image formed thereon to a conveyance path and a reading unit to read a test image of a sheet conveyed to the conveyance path. In addition, a controller determines an adjustment value for adjusting a geometric characteristic of an image to be formed by the image forming unit based on a reading result of the reading unit, controls the image forming unit to form the test image, controls the reading unit to read the sheet having the test image formed thereon, and determines an adjustment value for adjusting a geometric characteristic of an image to be formed by the image forming unit based on a reading result of the reading unit.

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.

According to an example, a calibration method may calculate a printhead distribution. The method may comprise printing a calibration pattern, detecting darkness values from the calibration pattern, assigning a darkness level to a plurality of printheads based on the darkness values, and calculating through a processor the printhead distribution that minimizes a variation of the darkness levels across the plurality of printheads.

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.

A method for correcting an error in image printing, the method includes receiving a reference digital image (RDI). Based on a predefined selection criterion, one or more regions in the RDI that are suitable for use as anchor features for sensing the error, are automatically selected. A digital image (DI) acquired from a printed image of the RDI, is received and the one or more regions are automatically identified in the DI. Based on the anchor features of the DI, the error is automatically estimated in the printed image. A correction that, when applied to the DI, compensates for the estimated error, is calculated. The estimated error is corrected in a subsequent digital image (SDI) to be printed, and the SDI having the corrected error, is printed.

In an example, there is provided a method and apparatus for controlling spit on page operation, the method comprising receiving at least one image to be printed, for each row of a plurality of rows of the image: identifying two or more pixels of the row of the image to be printed by a nozzle of a printhead, determining if a spacing between two consecutive pixels of the two or more pixels is greater than a threshold distance, and in response to a determination that the spacing between the two consecutive pixels is greater than the threshold distance, providing an indication that spit on page dots should be provided when printing the image.

An image forming apparatus includes an image forming unit configured to form an image on a sheet; an image processing unit configured to perform processing, which comprises correction of color misregistration, on image data for controlling the image forming unit to form the image; and a controller configured to instruct the image forming unit to perform calibration in a case where a component of the image forming unit is replaced. The image forming unit includes a storage unit, and is configured to acquire correction information to be used for the correction of color misregistration in the calibration to store the correction information in the storage unit, and the image processing unit includes a memory configured to store first image data, which is the image data before being processed, and second image data, which is obtained by compressing the image data after being processed.