Methods and apparatus relating to substructures for three-dimensional objects are described. In an example, a method comprises receiving a lattice model having a consistent dimensionality and determining a substructure model representing a three-dimensional material structure, the substructure model being based on the lattice model and specifying a variable material distribution. The substructure model may be populated with halftone threshold data to provide a three-dimensional halftone threshold matrix

A frequency adaptive descreening method includes obtaining a scan image of an original document, dividing a region of the scan image by analyzing frequency characteristics of the obtained scan image, estimating a resolution with respect to each of regions resulting from dividing the region according to the analyzed frequency characteristics, and adaptively performing filtering on the regions resulting from dividing the region by using the estimated resolution.

A frequency adaptive descreening method includes obtaining a scan image of an original document, dividing a region of the scan image by analyzing frequency characteristics of the obtained scan image, estimating a resolution with respect to each of regions resulting from dividing the region according to the analyzed frequency characteristics, and adaptively performing filtering on the regions resulting from dividing the region by using the estimated resolution.

Adjustment of a halftoning threshold can, in an example implementation, include assigning a relative energy value, relative to a reference energy value, to a location of a build area and adjusting a halftoning threshold based on the relative energy value.

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.

A binary image is generated from a multivalued image based on a threshold, an edge is extracted from the multivalued image, an edge image is generated by correcting a position of the extracted edge, and a synthetic binary image is generated by synthesizing the edge image and the binary image.

A binary image is generated from a multivalued image based on a threshold, an edge is extracted from the multivalued image, an edge image is generated by correcting a position of the extracted edge, and a synthetic binary image is generated by synthesizing the edge image and the binary image.

A method is disclosed. The method comprises receiving a matrix representation of a source image to be printed, the matrix representation defining a colorant value for each of a plurality of print addressable locations, wherein the colorant values are representative of amounts of print colorant to be delivered to the print addressable locations during a printing operation. The method may comprise identifying, by processing circuitry, a region in the matrix representation having a first print addressable location and an adjacent second print addressable location, wherein a difference between colorant values of the first print addressable location and the second print addressable location meets or exceeds a defined colorant value threshold. The method may comprise determining, by processing circuitry, an amount of treatment fluid to be delivered to each of the plurality of print addressable locations during the printing operation, wherein an amount of treatment fluid to be delivered in the identified region is determined to be greater than an amount of treatment fluid to be delivered to adjacent print addressable locations having colorant values which differ by less than the defined colorant value threshold. An apparatus and a machine-readable medium are also disclosed.

A method is disclosed. The method comprises receiving a matrix representation of a source image to be printed, the matrix representation defining a colorant value for each of a plurality of print addressable locations, wherein the colorant values are representative of amounts of print colorant to be delivered to the print addressable locations during a printing operation. The method may comprise identifying, by processing circuitry, a region in the matrix representation having a first print addressable location and an adjacent second print addressable location, wherein a difference between colorant values of the first print addressable location and the second print addressable location meets or exceeds a defined colorant value threshold. The method may comprise determining, by processing circuitry, an amount of treatment fluid to be delivered to each of the plurality of print addressable locations during the printing operation, wherein an amount of treatment fluid to be delivered in the identified region is determined to be greater than an amount of treatment fluid to be delivered to adjacent print addressable locations having colorant values which differ by less than the defined colorant value threshold. An apparatus and a machine-readable medium are also disclosed.

In a color printing environment, functions for printing color management are dissociated. An abstraction layer is also provided to facilitate setting and evaluation of all factors relating to color print and prediction.