Abstract: Example implementations relate to random wave mask generation. Some examples may distribute data points in a mask area based on a probability density function. The probability density function may have a maximum probability density located at a first edge and a second edge of the mask area. Some examples may also identify a wave curve that fits the data points. The wave curve may include oscillating waveforms of varying amplitudes. Some examples may also generate a random wave mask based on the wave curve.

Abstract: Examples include estimation of pen to paper spacing (PPS). Examples include an alignment pattern printed on a medium at a target speed, an optical scan procedure performed on the printed alignment pattern to determine values of cross-media misalignment for first and second portions of the alignment pattern, determination of a dynamic swath height error (DSHE) effect value based on the values of cross-media misalignment, and estimation of an amount of PPS based on the determined DSHE effect value and the target print speed.

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: The present disclosure discloses a page wide array (PWA) printer (20) particularly but not exclusively for performing print jobs while maximizing print bar performance uniformity within the printer. The PWA printer includes a print bar which can be moved laterally and a controller which causes the print bar to laterally move from a first to a second position and causes the nozzles within the print bar to print an image while the print bar is in the second position without modifying the lateral alignment of the image.

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: 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: Image processing transforms input multi-level image data into output image data having a smaller number of levels (the input and output image data represents images formed of cells). The image processing distributes quantization error of a target cell of the image to neighbour cells in proportions determined by a set of weights. The distribution excludes neighbour cells whose data level is less than a threshold value from receiving distributed quantization error, or allows just a fraction of the quantization error to be distributed to such neighbour cells.

Abstract: According to one example, there is provided a printing system. The printing system comprises a support having a plurality of spaced apertures and a colour sensor moveable to measure light from each aperture. The printing system further comprises a controller to control the colour sensor to measure characteristics of light emitted through each aperture, and to determine, for each aperture, light calibration data.

Abstract: Print media products comprise a top layer of a printing material comprising a plurality of holes distributed on the surface area thereof, and a bottom layer of a printing material comprising a plurality of holes distributed on the surface area thereof, the top layer being overlayed on and removably attached to the bottom layer such that an ink-receiving side of the top layer is exposed and an ink-receiving side of the bottom layer is in contact with the top layer, and such that the holes of the top layer are at least in part overlapped with print material of the bottom layer.

Abstract: A method and system of controlling at least one printbar in a printing system are described. The printing system has one or more of printbars (160, 190) distributed along a media transport. A first image including a reference pattern (240A, 240B) is generated on a print medium (150) with a first printbar (160). A detector (180) then detects a pattern on the print medium. The reference pattern and the detected pattern are used to determine a position of the first image relative to a second printbar (190). This position is used to configure nozzle data for a second image to be generated on the print medium by the second printbar.

Abstract: Print media products comprise a top layer of a printing material comprising a plurality of holes distributed on the surface area thereof, and a bottom layer of a printing material comprising a plurality of holes distributed on the surface area thereof, the top layer being overlayed on and removably attached to the bottom layer such that an ink-receiving side of the top layer is exposed and an ink-receiving side of the bottom layer is in contact with the top layer, and such that the holes of the top layer are at least in part overlapped with print material of the bottom layer.

Abstract: An image forming apparatus includes a normal consumption state, a low consumption state, and a fluid applicator unit. The fluid applicator unit may selectively provide a first set of drops of fluid to perform a printing routine in a print mode. The fluid applicator unit may also selectively provide a second set of drops of fluid to perform a service routine in a maintenance mode. An amount of the first set of drops of fluid to perform the printing routine and an amount of the second set of drops of fluid to perform the service routine may be less in the low consumption state than in the normal consumption state.

Abstract: A page-wide-array printer has a print unit including an array of print-heads, wherein a printing direction is defined by a relative movement between the print unit and a print medium during a printing process. The page-wide-array printer receives a continuous tone image and divides the continuous tone image into a series of slices along a printing direction. Halftone image data is generated from each of the slices using error diffusion halftoning. The error diffusion halftoning comprises processing, with regard to error diffusion, each slice pixel-by-pixel following a processing pattern mainly oriented along a main processing direction which is parallel to the printing direction. The page-wide-array printer prints the halftone image data along the printing direction.

Abstract: A page-wide-array printer has a print unit including an array of print-heads, wherein a printing direction is defined by a relative movement between the print unit and a print medium during a printing process. The page-wide-array printer receives a continuous tone image and divides the continuous tone image into a series of slices along a printing direction. Halftone image data is generated from each of the slices using error diffusion halftoning. The error diffusion halftoning comprises processing, with regard to error diffusion, each slice pixel-by-pixel following a processing pattern mainly oriented along a main processing direction which is parallel to the printing direction. The page-wide-array printer prints the halftone image data along the printing direction.

Abstract: A barcode on a medium is received. It is determined whether misalignment of a printhead of the printer is present based on bars in the barcode.

Abstract: An image forming apparatus includes a normal consumption state, a low consumption state, and a fluid applicator unit. The fluid applicator unit may selectively provide a first set of drops of fluid to perform a printing routine in a print mode. The fluid applicator unit may also selectively provide a second set of drops of fluid to perform a service routine in a maintenance mode. An amount of the first set of drops of fluid to perform the printing routine and an amount of the second set of drops of fluid to perform the service routine may be less in the low consumption state than in the normal consumption state.

Abstract: A barcode on a medium is received. It is determined whether misalignment of a printhead of the printer is present based on bars in the barcode.