Abstract: Certain examples described herein relate to halftone level adjustment for Neugebauer Primaries (NPs). In certain examples, halftone levels for NPs are obtained for a halftone for printing an image. It is determined whether the halftone corresponds to a line or an area fill. The halftone levels may be adjusted in response to these levels exceeding a printing attribute threshold. The printing attribute threshold may be dependent on whether the halftone corresponds to a line or an area fill. The image may then be printed using the adjusted halftone levels.

Abstract: Certain examples described herein relate to the control of colorants and treatments for printing. In certain examples image data, a colorant color mapping and one or more treatment color mappings is obtained. The colorant color mapping may be used to map the image data to colorant application values. The one or more treatment color mappings may be used to map the image data to treatment application values. The colorant application values and treatment application values may be used to generate discrete print control instructions to apply the set of colorants and set of treatments to a printing substrate.

Abstract: Certain examples described herein relate to halftone level adjustment for Neugebauer Primaries (NPs). In certain examples, halftone levels for NPs are obtained for a halftone for printing an image. It is determined whether the halftone corresponds to a line or an area fill. The halftone levels may be adjusted in response to these levels exceeding a printing attribute threshold. The printing attribute threshold may be dependent on whether the halftone corresponds to a line or an area fill. The image may then be printed using the adjusted halftone levels.

Abstract: A method is disclosed. According to some examples, the method comprises determining, by processing circuitry, a first element set to be associated with a print addressable location, the first element set comprising a first plurality of elements, wherein each element of the first plurality of elements identifies a print colorant or print colorant combination and is associated with a probability that the print colorant or print colorant combination identified by that element is to be applied to the associated print addressable location.

Abstract: In an example, a method includes acquiring data representing an article to be printed, the data comprising an element set associated with a print addressable location, the element set comprising a first element subset and a second element subset, wherein the first element subset and the second element subset comprise an element identifying a print material selection which is associated with a probability that the print material selection is to be applied to the associated print addressable location. The method further includes determining a first set of cumulative probability values associated with the elements of the first element subset and determining a second set of cumulative probability values associated with the elements of the second element subset. The first set of cumulative probability values may span a first predetermined value range and the second set of cumulative probability values may span a second predetermined value range.

Abstract: A method of calibrating a printing device, wherein the method comprises: associating a weighted printing value to each of a plurality of pixels, wherein associating a weighted printing value to each pixel comprises: obtaining, from a first calibration table, a first calibration value; obtaining, from a second calibration table, a second calibration value; obtaining first and second weighting factors, wherein the first weighting factor is obtained from a weighting table, generating the weighted printing value as the sum of the first calibration value weighted with the first weighting factor and the second calibration value weighted with the second weighting factor.

Abstract: Certain examples relate to converting between color spaces. A digital representation of an input color is pre-processed to convert the digital representation into a multidimensional node representing a region in the input color space and a set of adjustment values. The multidimensional node is mapped to a digital representation of an output color. The digital representation of the output color is adjusted using the set of adjustment values.

Abstract: In an example, a method includes acquiring data representing an article to be printed, the data comprising an element set associated with a print addressable location, the element set comprising a first element subset and a second element subset, wherein the first element subset and the second element subset comprise an element identifying a print material selection which is associated en with a probability that the print material selection is to be applied to the associated print addressable location. The method further includes determining a first set of cumulative probability values associated with the elements of the first element subset and determining a second set of cumulative probability values associated with the elements of the second element subset. The first set of cumulative probability values may span a first predetermined value range and the second set of cumulative probability values may span a second predetermined value range.

Abstract: In an example, an image processing system may include an identification engine, a map engine, and a control engine. In that example, the identification engine may identify a color mapping resource in response to a classification identifier corresponding to image data, the map engine may map the image data with the color mapping resource having color space clause corresponding to the classification identifier, and the control engine may generate control data for operating a print apparatus to print based on the color mapping resource.

Abstract: A method of recirculating fluid in a printhead die is provided. The method comprises generating ejection data specifying a nozzle of the printhead from which a drop is to be ejected and storing the ejection data in a first memory. Recirculation data is generated for the nozzle for which a recirculation operation is to be performed, and the recirculation data is stored in a second memory different from the first memory. Fluid is recirculated in the nozzle on the basis of the recirculation data in advance of ejecting a drop from the nozzle on the basis of the ejection data. The recirculation data is generated based on the respective ejection data for the nozzle.

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: A method of recirculating fluid in a printhead die is provided. The method comprises generating ejection data specifying a nozzle of the printhead from which a drop is to be ejected and storing the ejection data in a first memory. Recirculation data is generated for the nozzle for which a recirculation operation is to be performed, and the recirculation data is stored in a second memory different from the first memory. Fluid is recirculated in the nozzle on the basis of the recirculation data in advance of ejecting a drop from the nozzle on the basis of the ejection data. The recirculation data is generated based on the respective ejection data for the nozzle.

Abstract: In an example, an image processing system may include an identification engine, a map engine, and a control engine. In that example, the identification engine may identify a color mapping resource in response to a classification identifier corresponding to image data, the map engine may map the image data with the color mapping resource having color space clause corresponding to the classification identifier, and the control engine may generate control data for operating a print apparatus to print based on the color mapping resource.

Abstract: An example system includes a controller. The controller is to determine a first end point of a previous frame in a first image. The first image is to be printed on a first ribbon. The controller is to determine a second end point of the previous frame in a second image to be printed on a second ribbon. The controller is to create a current frame containing first image data from the first image starting after the first end point, second image data from the second image starting after the second end point, and third image data from a beginning of the first image. The system includes an image engine to form an image corresponding to the current frame on a medium.

Abstract: Examples relate to providing synchronized look-up table loading. In some examples, a print job is processed using an initial look-up table in processor memory. In response to the processing of the print job reaching a buffer trigger row of a portion of the print job, look-up metadata is accessed to locate a next look-up table. At this stage, the next look-up table is dynamically loaded into the processor memory as the processor continues to process the print job, where the processing of the print job begins using the next look-up table after a target row of the portion of the print job is reached.

Abstract: The present disclosure relates to a printhead control system for a printer, wherein the printer includes at least one printhead comprising a plurality of nozzles for ejecting printing fluid, wherein the nozzles include high drop weight nozzles and low drop weight nozzles ejecting drops of different drop weight, and are each arranged to eject printing fluid on a print medium such as to print images in frame areas of the print medium and such as to clean nozzles in spit bar areas of the print medium; the printer further includes a transport unit for moving the print medium relative to the printhead, wherein the print medium includes frame areas for printing images and spit bar areas for cleaning the nozzles; the printhead control device including: a module to determine a first group of said nozzles located over a frame area of the print medium and a second group of said nozzles located over a spit bar area of the print medium; a module to operate the high drop weight nozzles of the first group such as to eject

Abstract: Examples relate to providing synchronized look-up table loading. In some examples, a print job is processed using an initial look-up table in processor memory. In response to the processing of the print job reaching a buffer trigger row of a portion of the print job, look-up metadata is accessed to locate a next look-up table. At this stage, the next look-up table is dynamically loaded into the processor memory as the processor continues to process the print job, where the processing of the print job begins using the next look-up table after a target row of the portion of the print job is reached.

Abstract: An example system includes a controller. The controller is to determine a first end point of a previous frame in a first image. The first image is to be printed on a first ribbon. The controller is to determine a second end point of the previous frame in a second image to be printed on a second ribbon. The controller is to create a current frame containing first image data from the first image starting after the first end point, second image data from the second image starting after the second end point, and third image data from a beginning of the first image. The system includes an image engine to form an image corresponding to the current frame on a medium.

Abstract: Examples relate to providing synchronized look-up table loading. In some examples, a print job is processed using an initial look-up table in processor memory, in response to the processing of the print job reaching a buffer trigger row of a portion of the print job, look-up metadata is accessed to locate a next look-up table. At this stage, the next look-up table is dynamically loaded into the processor memory as the processor continues to process the print job, where the processing of the print job begins using the next look-up table after a target row of the portion of the print job is reached.

Abstract: The present disclosure relates to a printhead control system for a printer, wherein the printer includes at least one printhead comprising a plurality of nozzles for ejecting printing fluid, wherein the nozzles include high drop weight nozzles and low drop weight nozzles ejecting drops of different drop weight, and are each arranged to eject printing fluid on a print medium such as to print images in frame areas of the print medium and such as to clean nozzles in spit bar areas of the print medium; the printer further includes a transport unit for moving the print medium relative to the printhead, wherein the print medium includes frame areas for printing images and spit bar areas for cleaning the nozzles; the printhead control device including: a module to determine a first group of said nozzles located over a frame area of the print medium and a second group of said nozzles located over a spit bar area of the print medium; a module to operate the high drop weight nozzles of the first group such as to eject