Hewlett-packard Development Company, L.p.

Sergio Etchebehere Juan

Peter Morovic

Jan Morovic

Javier Maestro Garcia

Hector Gomez Minano

Pau Costal Fornells

Pere Josep Canti Nicolas

Pere Gasparin Talarn

Systems, apparatuses, and methods may provide for technology to control the printing of halftoning screen signatures for various levels of prints. For example, such prints may include regular edition prints or limited edition prints. During printing, a first halftoning screen is associated with one or more of the regular edition prints and a second halftoning screen is associated with the limited edition print, in some implementations. The second halftoning screen has a spatial frequency that is substantially the same as the first halftoning screen while having a spatial signature different from the first halftoning screen. Additionally, the second halftoning screen further may have spectral properties that are substantially the same as the first halftoning screen. During printing, two different printed copies of an image are formed using the first halftoning screen and the second halftoning screen.

Custom halftone for limited edition prints

Mask entries for each of a plurality of passes over which print fluid drops are to be dispensed for printing an image are generated based on different types of masks and based on image data for the image. Print fluid drop dispensation for a pixel for which the mask entries for a given pass specify repeated print fluid drop dispensation is moved to a mask entry for an adjacent pass that does not specify print fluid drop dispensation for the pixel. Ejection of print fluid to print the image is caused based on the generated mask entries.

Print fluid drop dispensation mask with entry moved to entry for adjacent pass to avoid repeated dispensation for a pixel per pass

A system encodes a plurality of colorant vectors of a printer in a Neugebauer Primary area coverage (NPac) vector for use in selecting colorants to output an image by the printer. The encoding includes using a function that relates the plurality of colorant vectors to an NP matrix including a plurality of sets of NPs that correspond to different colorant vectors of the plurality of colorant vectors, and determining the NPac vector based on achieving an objective for the function.

Encoding plural colorant vectors in a Neugebauer Primary area coverage vector

Certain examples described herein relate to adjusting a printing system. In certain cases, a lookup table, LUT, is obtained where the lookup table comprises a plurality of nodes that map a plurality of input first color space values to a plurality of Neugebauer Primary area coverage, NPac, vectors in a second color space and each NPac vector comprises at least one Neugebauer Primary, NP. Each NPac vector in the LUT is adjusted by the determination of a colorimetric value of the NPac vector and the modification of the NPac vector based on a characteristic of the corresponding at least one NP and the colorimetric value such that the modification is specific to the NPac vector. The lookup table is updated with the modified NPac vector and stored for referral by the printing system in any future printing.

Color calibration in a printing system

A hybrid-masked halftone area Neugebauer separation (HANS) pipeline for a printing system is constructed. A number of Neugebauer Primaries (NPs) of and a halftone pattern to employ within the pipeline are selected according to specified ink interaction constraints during printing system ink output onto media, at a native resolution of the printing system. An NP area coverage (NPac)-based lookup table (LUT) and a pre-LUT color profile to employ within the pipeline are constructed according to first specified ink coverage and usage constraints during the ink output, at the native resolution. LUT post-processing and post-halftone pattern masking to employ within the pipeline are determined according to second specified ink coverage and usage constraints during the ink output, at the native resolution.

Hybrid-masked halftone area Neugebauer separation (HANS) pipeline

Certain examples described herein relate to a color processing apparatus and a method of generating configuration data for a color rendering device. The color rendering device operates based on color state instructions indicating output color states for portions of a rendered output. Render data may be generated by applying a halftone matrix and color data may indicate probability values for the output color states for input image areas corresponding to the portions of the rendered output. In described examples, configuration data defines an order of output color states for application of the halftone matrix. In the order, the output color states are grouped within the data based on color properties of a rendered output and an order within the clusters is based on colorant composition.

Clustering colors for halftoning

A print calibration system comprising a printing device to apply print material to a print target in a printing process, a memory for storing a lookup table; and a processor. The processor causes the printing device to print calibration points for reproducing a color ramp, by receiving a plurality of Neugebauer Primary area coverage ('NPac') points representing the plurality of calibration points and determining a hue angle and color space based on the NPac points. A plurality of nodes distributed between a first node and a second node of a sectional representation of the NPac points is determined. A lookup table is generated based on a relationship between the plurality of nodes and the NPac points for use during the printing process, wherein the lookup table comprises values to map between a first color space and a second color space, the lookup table is then provided to the printing device.

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Sant Cugat del Valles, Spain

Sergio Etchebehere Juan