An example system in accordance with an aspect of the present disclosure includes a halftone engine and a gray value engine. The halftone engine is to apply halftoning to an image recursively across a plurality of levels of image scales and spatial resolutions, to generate a pattern that is at least quasi-periodic across the plurality of levels. The gray value engine is to substitute gray values recursively for at least a portion of the halftoning.

An image forming control method is applied to an image forming apparatus. The method includes, after the image forming apparatus is connected to an image processing apparatus, sending information related to a halftone parameter of the image forming apparatus to the image processing apparatus for storage, obtaining halftone-processed intermediate data that is to be printed sent by the image processing apparatus, and outputting the halftone-processed intermediate data that is to be printed to an image generator to perform an image forming operation.

A method of processing data for additive manufacturing of a 3D object comprises: receiving graphic elements defining a surface of the object, and an input color texture to be visible over a surface of the object; transforming the elements to voxelized computer object data; constructing a 3D color map having a plurality of pixels, each being associated with a voxel and being categorized as either a topmost pixel or an internal pixel. Each topmost pixel is associated with a group of internal pixels forming a receptive field for the topmost pixel. A color-value is assigned to each topmost pixel and each internal pixel of a receptive field associated with the topmost pixel, based on the color texture and according to a subtractive color mixing. A material to be used during the additive manufacturing is designated based on the color-value.

An example image forming apparatus includes a print engine to form an image by using toners of different colors, a memory to store toner quantity information of the different colors of toners, and a processor to perform a print job by reducing a use of a toner with a small toner residual quantity ratio when a difference in a residual quantity ratio of the toner for each color is greater than or equal to a determined value on the basis of the stored toner quantity information.

An example image forming apparatus includes a print engine to form an image by using toners of different colors, a memory to store toner quantity information of the different colors of toners, and a processor to perform a print job by reducing a use of a toner with a small toner residual quantity ratio when a difference in a residual quantity ratio of the toner for each color is greater than or equal to a determined value on the basis of the stored toner quantity information.

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. The method may comprise determining, by processing circuitry, a second element set to be associated with the print addressable location, the second element set comprising a second plurality of elements, wherein each element of the second plurality of elements identifies a print agent or print agent combination and is associated with a probability that the print agent or print agent combination identified by that element is to be applied to the associated print addressable location. The method may comprise determining, by processing circuitry, a combined element set based on the first element set and the second element set. An apparatus and a machine-readable medium are also disclosed.

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. The method may comprise determining, by processing circuitry, a second element set to be associated with the print addressable location, the second element set comprising a second plurality of elements, wherein each element of the second plurality of elements identifies a print agent or print agent combination and is associated with a probability that the print agent or print agent combination identified by that element is to be applied to the associated print addressable location. The method may comprise determining, by processing circuitry, a combined element set based on the first element set and the second element set. An apparatus and a machine-readable medium are also disclosed.

Such internal decoration is implemented that an object looks a target color as viewed in any direction, and that the object is colored and has image depiction in any cross-section. A method is provided for producing a three-dimensional object by extruding a build material to form a layer corresponding to each of cross-sections obtained by slicing a target object by a plurality of parallel planes, and depositing such layers in sequence so as to form the three-dimensional object. A white material 15 and one or two or more decoration materials 13 of colors other than white, which solidify wider a predetermined condition after extruded from nozzles, are used as the build material. The decoration materials 13 and the white material 15 are mixed to form the layer.

An apparatus comprises a unit configured to generate gradation data corresponding to an achromatic color generated by combining two or more colors among a plurality of colors, for an excess amount of a total gradation value exceeding a predetermined value, the total gradation value being a sum of gradation values of the plurality of colors used for recording a pixel of interest, and generate gradation data corresponding to the plurality of colors, based on the generated gradation data corresponding to the achromatic color; and a unit configured to quantize the generated gradation data, and generate data to control recording of dots corresponding to the pixel of interest. The predetermined value is a gradation value indicating whether or not to record the dots in an overlapping manner, in case that the dots corresponding to the total gradation value are recorded.

In an example, a method includes determining, by processing circuitry, an element set to be associated with a print addressable location for printing an article in a one-pass print mode. The element set may comprise a plurality of elements, wherein each element identifies a print material or print material combination and is associated with a probability that the print material or print material combination identified by that element is to be applied to the associated print addressable location. Determining the element set for printing in a one-pass print mode may comprise favouring elements identifying individual print materials over elements identifying print material combinations.