Abstract: 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.

Abstract: A print material usage estimation device may comprise a first usage meter to measure a first print material usage associated with print material deposition on a print medium over a specified time period. 5 The print material usage estimation device may further comprise a second usage meter to measure a second print material usage associated with other printer processes over the specified time period. The print material usage estimation device may further comprise a ratio calculator to calculate a ratio between second print material usage and first print material usage over the specified time period. The print 10 material usage estimation device may further comprise an estimator to estimate total print material usage for an instructed print job based on a predetermined first print material usage for the print job and the calculated ratio.

Abstract: An image processing method is disclosed. The method includes receiving information relating to a print component to be used to print a target image; determining, based on the received information relating to the print component, half-toning parameters to be applied when generating a half-tone representation of the target image; and generating, using the determined half-toning parameters, a half-tone representation of the target image. An apparatus and a machine-readable medium are also disclosed.

Abstract: In an example, a processor comprises an ancillary print agent distribution module to determine instructions for a print control module. The print control module may be to control the distribution of print agent onto a first region of a layer of build material in an object fabrication chamber in an additive manufacturing process in which at least one object is generated by selective solidification of each of a plurality of layers of build material and the selective solidification of build material is determined by the distribution of at least one print agent. The instructions determined by the ancillary print agent distribution module may be to cause the print control module to control the distribution of print agent in a second region of a layer of build material in an object fabrication chamber as part of a process which is ancillary to object generation. The first and second regions may be spatially distinct.

Abstract: A circuit 108 for controlling a plurality of fluid dispense nozzles 202(N), the circuit 108 to change an order in which the fluid dispense nozzles 202(N) are actuated.

Abstract: Print apparatus is controlled to execute a print operation comprising a plurality of print sweeps onto a print zone of a print substrate and a corresponding plurality of print advances of the print substrate between successive print sweeps. Print apparatus is controlled to execute an intermediate cutting operation between a pre-cut print sweep and a successive post-cut print sweep of the plurality of print sweeps.

Abstract: Cells of an n-dimensional object are indexed. A plurality of indexing digits are grouped for each axis of the n dimensions of the n-dimensional object. A first indexing digit of a given group is allocated to each of at least two cells resulting from at least one subdivision of the dimension of the object along the axis of the given group; and an mth subsequent indexing digit of the given group is allocated to any subsequent at least two cells resulting from any subsequent at least one subdivision of at least one cell of the at least two cells resulting from the m?1th subdivision of the dimension of the object along the axis of the given group.

Abstract: In some examples, an imaging device may include a controller including processing circuitry to detect, a first quantity of rows of pixels to be included as a first band of a contone image, process the pixels of each row of the first band in parallel raster order, detect a second quantity of rows of pixels to be included as a second band of the contone image; and process the pixels of each row of the second band in response to the completion of the pixels of the first band, where the rows of the second band are processed in parallel in serpentine order with respect to the first band.

Abstract: According to an example, an apparatus may include a processor and a memory. The memory may have stored thereon machine readable instructions that may cause the processor to access an initial halftone image of a three-dimensional (3D) object, the initial halftone image being generated from a continuous tone image of the 3D object. The instructions may also cause the processor to iteratively modify voxel data for the initial halftone image to identify updated voxel data that more accurately corresponds to the continuous tone image than the initial halftone image and to generate halftone image printing data for the 3D object containing the updated voxel data.

Abstract: Print apparatus is controlled to execute a print operation comprising a plurality of print sweeps onto a print zone of a print substrate and a corresponding plurality of print advances of the print substrate between successive print sweeps. Print apparatus is controlled to execute an intermediate cutting operation between a pre-cut print sweep and a successive post-cut print sweep of the plurality of print sweeps.

Abstract: According to an example, an apparatus may include a processor and a memory. The memory may have stored thereon machine readable instructions that may cause the processor to access an initial halftone image of a three-dimensional (3D) object, the initial halftone image being generated from a continuous tone image of the 3D object. The instructions may also cause the processor to iteratively modify voxel data for the initial halftone image to identify updated voxel data that more accurately corresponds to the continuous tone image than the initial halftone image and to generate halftone image printing data for the 3D object containing the updated voxel data.

Abstract: An example media handling system provides a print media (111) along a media path (131) and at least part of the media handling system includes an adhesive material for locating the print media (111) on the at least part of the media path (131).

Abstract: In an example, a method includes receiving print data indicative of an image to be printed on a substrate. The print data may indicate an image portion in which an image is present and a void portion in which the image is absent. An amount of background print agent to be applied to a region of the substrate corresponding to the locations of the image portion and the void portion on the substrate when the image is printed may be determined. In examples, the amount of background print agent determined to be applied to a region of the substrate corresponding to the location of the void portion on the substrate when the image is printed is greater than the amount of a background print agent to be applied to the region of the substrate corresponding to the location of the image portion on the substrate when the image is printed.

Abstract: In some examples, a printing system includes a printhead comprising a nozzle array including plural columns of nozzles to deliver printing fluid to a print medium, wherein nozzles in a first column of the columns are offset from nozzles in a second column of the columns. A controller is to control printing onto the print medium using the printhead by, for each respective pass of a plurality of passes of the printhead over the print medium, controlling an advance of the print medium for a print mask pattern that controls firing of the nozzles of the printhead, where the controlled advance of the print medium causes nozzles from different columns of nozzles of the nozzle array to deliver dots of printing fluid to a given row of a swath in successive passes of the plurality of passes.

Abstract: In an example, a method includes receiving print data indicative of an image to be printed on a substrate. The print data may indicate an image portion in which an image is present and a void portion in which the image is absent. An amount of background print agent to be applied to a region of the substrate corresponding to the locations of the image portion and the void portion on the substrate when the image is printed may be determined. In examples, the amount of background print agent determined to be applied to a region of the substrate corresponding to the location of the void portion on the substrate when the image is printed is greater than the amount of a background print agent to be applied to the region of the substrate corresponding to the location of the image portion on the substrate when the image is printed.

Abstract: In an example, a processor comprises an ancillary print agent distribution module to determine instructions for a print control module. The print control module may be to control the distribution of print agent onto a first region of a layer of build material in an object fabrication chamber in an additive manufacturing process in which at least one object is generated by selective solidification of each of a plurality of layers of build material and the selective solidification of build material is determined by the distribution of at least one print agent. The instructions determined by the ancillary print agent distribution module may be to cause the print control module to control the distribution of print agent in a second region of a layer of build material in an object fabrication chamber as part of a process which is ancillary to object generation. The first and second regions may be spatially distinct.

Abstract: Example implementations relate to swath height error compensation. Some examples may determine a density of an image to be printed in an overlap area of a printing material. The overlap area may include target pixels capable of being printed by a first set of drop ejection elements and a second set of drop ejection elements that are redundant to the first set of drop ejection elements. Some implementations may also determine a mask to apply to the first and second set of drop ejection elements based on the determined density, and the mask may designate at least one additional drop to apply to at least one target pixel in the overlap area by at least one of the first and second set of drop ejection elements. Some implementations may also apply the mask to the first set of drop ejection elements and the second set of drop ejection elements.

Abstract: In some examples, a printing system includes a printhead comprising a nozzle array including plural columns of nozzles to deliver printing fluid to a print medium, wherein nozzles in a first column of the columns are offset from nozzles in a second column of the columns. A controller is to control printing onto the print medium using the printhead by, for each respective pass of a plurality of passes of the printhead over the print medium, controlling an advance of the print medium for a print mask pattern that controls firing of the nozzles of the printhead, where the controlled advance of the print medium causes nozzles from different columns of nozzles of the nozzle array to deliver dots of printing fluid to a given row of a swath in successive passes of the plurality of passes.

Abstract: Cells of an n-dimensional object are indexed. A plurality of indexing digits are grouped for each axis of the n dimensions of the n-dimensional object. A first indexing digit of a given group is allocated to each of at least two cells resulting from at least one subdivision of the dimension of the object along the axis of the given group; and an mth subsequent indexing digit of the given group is allocated to any subsequent at least two cells resulting from any subsequent at least one subdivision of at least one cell of the at least two cells resulting from the m?1th subdivision of the dimension of the object along the axis of the given group.

Abstract: Example implementations relate to swath height error compensation. Some examples may determine a density of an image to be printed in an overlap area of a printing material. The overlap area may include target pixels capable of being printed by a first set of drop ejection elements and a second set of drop ejection elements that are redundant to the first set of drop ejection elements. Some implementations may also determine a mask to apply to the first and second set of drop ejection elements based on the determined density, and the mask may designate at least one additional drop to apply to at least one target pixel in the overlap area by at least one of the first and second set of drop ejection elements. Some implementations may also apply the mask to the first set of drop ejection elements and the second set of drop ejection elements.