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: 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: In an example, a method includes measuring a temperature of a plurality of regions of a layer of build material in an additive manufacturing apparatus to provide initial temperature values. For each of a plurality of regions which comprise build material which is intended to fuse, an average temperature value of a plurality of neighbouring regions may be determined and the initial temperature values may be replaced with the average temperature value. Based on the replacement temperature values, a representative temperature of an area of the layer of build material may be determined and a heat source may be controlled based on the representative temperature.

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: A method comprises receiving object model data in an original coordinate system to print within a predefined usable build volume of a three dimensional printer. The method comprises receiving at least one compensation factor for the object model data to compensate for any shrinking of an object. The method comprises scaling the object model data by the at least one compensation factor to provide printable object model data. The scaling is performed with reference to an origin at a centre of the usable build volume.

Abstract: In an example, a method includes acquiring, at a processor, a first data model and a second data model. The first data model comprises a representation of at least one property of at least part of a first object and the second data model comprises a representation of at least one property of at least part of a second object. The first and second objects are to be generated in a common additive manufacturing operation. The method may include generating a first print layer model and a second, different, print layer model using the processor by combining at least parts of the first data model and the second data model and generating additive manufacturing instructions based on the first print layer model and the second print layer model.

Abstract: In an example, a method includes receiving, at a processor, data representing at least part of an object to be manufactured in a layer-by-layer manufacturing process. A serialised octree representation of at least part of the object may be generated from the data. In the serialised octree representation, nodes are ordered such that (i) a node representing a volume which includes a layer of the object to be generated earlier in an intended order of object generation precedes a node representing a volume which consists of layer(s) of the object to be generated subsequently; (ii) nodes representing a volume which includes a given layer of the object are ordered based on a level of the nodes within the octree representation, wherein parent nodes appear before descendent nodes; and (iii) nodes representing a volume which includes a given layer of the object and being of the same level within the octree representation are ordered according to a location encoding pattern.

Abstract: In an example, a method includes receiving, at a processor, data representing a three dimensional object. Using the processor, a modified data representation of the three dimensional object may be determined wherein, in the modified data representation, the three dimensional object is represented in terms of homogenous sub-volumes. Each homogenous sub-volume is homogenous with respect to a predetermined attribute and contains locations which are within a common object boundary distance band of plurality of object boundary distance bands, wherein at least two object boundary distance bands partially overlap.

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: In some examples herein, control data is for application of treatment fluid on a treatment substrate location surrounding a substrate dot corresponding to a first pixel of the digital image. Treatment fluid is ejected on the treatment substrate location if a metric value computed from pixel values of a set of pixels in the neighborhood of the first pixel is above a threshold level.

Abstract: A number of colors in a predefined region of an image to be compressed are determined. The predefined region has a plurality of pixels. In response to determining that the number of colors is greater than a first predefined threshold, a lossy compression process is selected dependent on a number of pixels in the predefined region having a predefined color. The selected lossy compression process is applied to the predefined region.

Abstract: A printing system and method to process image data is disclosed. The printing system includes an identification module and image pipeline module include a linear threshold array algorithm and a halftoning algorithm to process the image data. An image pipeline module applies a linear threshold array algorithm to line regions and a halftoning algorithm to the non-line regions.

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: In some examples herein, control data is for application of treatment fluid on a treatment substrate location surrounding a substrate dot corresponding to a first pixel of the digital image. Treatment fluid is ejected on the treatment substrate location if a metric value computed from pixel values of a set of pixels in the neighborhood of the first pixel is above a threshold level.

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: An image pipeline execution method includes analyzing at least one attribute of an image and determining an image type of the image from a set of predetermined image types based on the analyzing the at least one attribute of the image. The image pipeline execution method also includes dynamically establishing an image pipeline to process the image based on the image type and executing the image pipeline to print the image.

Abstract: A printing system and method to process image data is disclosed. The printing system includes an identification module and image pipeline module include a linear threshold array algorithm and a halftoning algorithm to process the image data. An image pipeline module applies a linear threshold array algorithm to line regions and a halftoning algorithm to the non-line regions.

Abstract: A color input image comprising a plurality of pixels, each pixels encoded in RGB color space, is processed to convert the RGB pixels to another color space domain for printing the color input image. The number of colors within a cell of the input image is reduced. Each cell comprises an N×M array of pixels and the number of colors is reduced to a maximum of b source colors, wherein b is a positive integer equal to or greater than 2. Each of the resulting colors of each cell is calibrated to generate a printable color. The cells are then processed to convert the pixels of each cell into another color space, for example, to determine ink vectors, in another color space, for each calibrated color.

Abstract: A method of increasing data flow to a printing device includes, with a first raster image processor, converting a document into a first bitmap having a first dot density and representing a black color plane of the document; with a second raster image processor, converting the document into a second bitmap at a second dot density that is a relatively lower dot density than that of the first bitmap, the second bitmap representing other color planes of the document; and transmitting data of the first and second bitmaps to a printing device for printing to a print medium.

Abstract: A method of increasing data flow to a printing device includes, with a first raster image processor, converting a document into a first bitmap having a first dot density and representing a black color plane of the document; with a second raster image processor, converting the document into a second bitmap at a second dot density that is a relatively lower dot density than that of the first bitmap, the second bitmap representing other color planes of the document; and transmitting data of the first and second bitmaps to a printing device for printing to a print medium.