A digital printing system having a linear printhead includes corrections for in-track position errors. A data processing system implements a method for determining an in-track position function which includes printing a test target including a plurality of alignment marks, automatically analyzing a captured image of the printed test target to determine a measured in-track position for each of the alignment marks, comparing the measured in-track positions for the alignment marks to reference in-track positions to determine measured in-track position errors, and determining an in-track position correction function responsive to the measured in-track position errors. The in-track position correction function specifies in-track position corrections to be applied as a function of cross-track position. A corrected digital image is determined by resampling an input digital image responsive to the in-track position correction function.

An image forming apparatus includes an image forming section that forms a pattern image for detecting image-position displacement with respect to a lenticular lens sheet. The pattern image includes periodic images in each of which set images, each including two or more images of different shades and having a length equal to a lens pitch of the lenticular lens sheet, are arranged in a lens transverse direction of the lenticular lens sheet. The periodic images are arranged in a lens longitudinal direction of the lenticular lens sheet so as to be gradually shifted from one another in the lens transverse direction by a distance less than the lens pitch.

In one example of the disclosure, a first print engine is caused to print a first image in a first set of sectors of a substrate. A second print engine is caused to print a second image in a second set of sectors of the substrate. The second print engine is caused to print a cover-up image over an incidence of the first image printed by the first print engine. The second print engine is caused to print a calibration image upon the cover-up image.

A test chart is obtained by printing a test chart image using an image forming apparatus for skew measurement of the image forming apparatus. The test chart includes a first scale image that includes a scale along a secondary scanning direction and a second scale image that includes a scale along the secondary scanning direction. The first and second scale images are arranged along a primary scanning direction. When a top-end part of the test chart is folded back, a top end of the test chart indicates different values from each other on the first and second scale images in accordance with a skew angle.

A measurement apparatus includes a first conveyance path, a second conveyance path, a measuring portion, a third conveyance path and a sheet stacking portion. A sheet discharged out of an image forming apparatus is conveyed toward a downstream apparatus through the first conveyance path. The second conveyance path is branched from the first conveyance path, extended below the first conveyance path, and merged with the first conveyance path. The measuring portion is disposed on the second conveyance path. The third conveyance path is provided above the first conveyance path and is configured to convey the sheet from which a test image has been measured by the measuring portion in the second conveyance path. The sheet stacking portion is provided above the first conveyance path, and the sheet discharged out of the third conveyance path is stacked on the sheet stacking portion.

An image forming apparatus, which is configured to execute calibration for controlling an image forming condition, the image forming apparatus including: a first detection unit configured to detect an environmental state in which the image forming apparatus is installed; a prediction unit configured to predict, based on a plurality of detection results detected by the first detection unit in a first period, a change in the environmental state in a second period after the first period; and a setting unit configured to set a timing of executing the calibration in the second period based on the change in the environmental state predicted by the prediction unit.

Pixel blocks of a user-generated print job raster page are clustered into raster color clusters, and pixel blocks of a corresponding scanned page are clustered into scanned color clusters. For each raster color cluster, if a color difference between the cluster and a corresponding scanned color cluster is greater than a threshold, color fading of the cluster is determined from simulated depletion of each colorant of a printing device, and a likely depleted colorant is determined based on the corresponding scanned color cluster and the determined color fading. A most likely depleted colorant is determined from the likely depleted colorant predicted for each raster color cluster for which the determined color difference is greater than the threshold.

An image processing apparatus includes a scanner configured to read an image formed on a sheet along a reading direction and generate image data thereof, and a processor. The processor is configured to select a first region of the generated image data into which a first image indicating the reading direction is to be combined, set a pixel value of the first image in accordance with a pixel value of a pixel around the first region, and combine the first image having the determined pixel value into the first region of the image data and output the combined image data.

A method of operating a selective deposition-based additive manufacturing system capable of building a three-dimensional (3D) part includes developing a first layer using at least one electrostatographic engine, conveying the first layer from the at least one EP engine to a transfusion assembly, determining an anticipated transfusion overlay error for the first layer, determining whether the anticipated transfusion overlay error exceeds an overlay error specification, discarding the first layer after determining that the anticipated transfusion overlay error exceeds the overlay error specification, developing a successive layer using the at least one electrostatographic engine, conveying the successive layer from the at least one electrostatographic engine to the transfusion assembly, and transfusing the successive layer on a part build surface using the transfusion assembly to build the 3D part in a layer-by-layer manner on a part build platform.

An image forming unit forms an image based on image data. A roller conveys the sheet from a tray. A reading unit reads the sheet. A controller controls the image forming unit to form a test image on one side of the sheet, controls the roller to convey the sheet on which the test image has been formed, obtains first read data relating to a read result of a first surface of the sheet on which the test image is formed, obtains second read data relating to a read result of a second surface from the first read data and the second read data, selects read data relating to a read result relating to the test image, controls, based on the selected read data, a density of an output image to be formed by the image forming unit.