Agfa Graphics Nv

Agfa Gevaert Nv

Agfa Nv

Agfa Offset Bv

Koen Vande Velde

Marc Mahy

Paul A Delabastita

Luc Minnebo

Kris Vangeel

Wim Helsen

Dmitry Tunitsky

Erik Van Geel

A colorant splitting method performed by a colorant splitter wherein an n-dimensional color in an n-dimensional colorant space is converted to an m-dimensional colorant space by a colorant splitting curve set and wherein the colorant splitting curve set is the result of interpolation of a set of colorant splitting curve sets to improve the image quality of reproduced content and to improve the usage of total coverage of the colorants.

Colorant splitting method

A standard printer characterization target is printed with a reference printer and measured. From the measured data, a model is derived that describes for each ink the behavior of each individual ink in combination with different combinations of the other inks. In order to reduce the complexity for obtaining a printer model of a second printer, a second target is printed that includes only a subset of the color patches in the standard printer characterization target. With the model and interpolation, it is possible to reconstruct colorimetric data for missing color patches in the reduced target.

Method for characterizing a printer

A method including the steps of selecting an n-ink model for a color device, for transferring a set of colorant values in colorant space to a set of color values in color space; selecting a printer characteristic of the n-ink model, wherein the printer characteristic indicates the regularity of the n-ink model; evaluating, for the n-ink model, a set of one or more values and/or ranges for the printer characteristic, thus determining the regularity of the n-ink model; and modifying the n-ink model such that the modified n-ink model is regular, if, based on the evaluation, the n-ink model was not regular.

System and method for regularizing an ink model for a color device

A method for creating a set of metameric printed color patches on a color printer enables visual assessment under a specific illuminant if the colors of a printed product have faded.

Method and apparatus for calculating metameric colors

A method for making a dot for dot proof for a printing device, such as a press, on another device, such as a proofer, the method including (a) inputting, at pixel level, binary or pseudo-binary data indicating at a given pixel screened colorant values of the printing device; (b) inputting contone colorant values of the printing device indicating a color in a neighborhood of the given pixel; (c) outputting colorant values for the other device at the given pixel, based on the input contone colorant values and on the input binary or pseudo-binary data, such that a color match is obtained with a given color behavior of the printing device.

Method for making a dot for dot proof

A method and apparatus for creating a print file for printing a 3-D print using a 3-D printing system is described, the 3-D print comprising a plurality of 3-D structures printed on a substrate, each 3-D print structure having a height with respect to the substrate. A two-dimensional source image is input comprising a plurality of image pixel areas. A filtered image is obtained by applying a topographic operator to the source image to generate for every image pixel a representation of a pixel height profile, the pixel height profile corresponding to cross-sections through a 3-D print structure which is to be formed by 3-D printing. Thereby definitions of a plurality of image layers are generated from the filtered image for printing using the 3-D printing system. The print file is output based on the plurality of image layers. The topographic operator has the following property: any cross-section through a solid section of a 3-D structure at a second level in the 3-D print structure which is closer to the substrate than a first level has an area which is equal to or larger than the area of the cross-section of the 3-D structure at the first level.

Method and apparatus for creating 3D-prints and a 3-D printing system

A method for processing a digitized continuous tone image for reproducing the image by a printing device, including (a) inputting a tone value of an input pixel of the image; (b) applying a plurality of levelsplit curves to the tone value, thus obtaining a plurality of level values, wherein each specific levelsplit curve of the curves corresponds to a level defined by (i) a combination of a dot density and a dot area; or (ii) an overlap of a plurality of such combinations; (c) inputting the plurality of level values to an error diffuser for obtaining an output pixel value for reproducing the image; wherein a fraction of the output pixels to be filled by an overlap of levels depends on the level values and is independent of the error diffuser.

Full control multilevel error diffusion

Printing masters are produced by use of an inkjet printing system. The smallest halftone dot size which can be printed by the inkjet printing system is larger than the size of a pixel of the recording grid defined by the addressability of the printing device. Inferior image quality and graininess caused by standard error diffusion algorithms in this system can be counteracted by using a constraint correlation error diffusion system. Out of the complete set of all possible intensity level combinations for reproducing a pixel a subset is selected based upon the multilevel halftoning process of a quantized scalar value which is a function of at least one of the input pixel values of the corresponding colour component pixels. Preferably the scalar value represents the brightness or ink amount allocations.

Constraint correlation for computer to plate inkjet system

Separation of a color into values for colorants in colorant space can be done easily when color correction and color separation are done in separate steps, where the color is defined as a set of values in a trajectory space, and trajectories include points for which ink behavior during color separation is known. Colorant values for the color are determined by interpolation using values of the color located in trajectory space, and known values and corresponding colorant values of the trajectory points. Trajectories are preferably color axes dividing the trajectory space into tetrahedral. Colorant values may be corrected using techniques such as colorant replacement or colorant splitting prior to color separation. The color separation process can be calibrated using a test target.

Colour separation method

A multilevel printing process can be calibrated by: measuring a small number of recorded patches obtaining data points characterising the printing process, modeling a gradation of the printing process with a model curve incorporating different gradation behaviour of the printing process in different regimes based upon the obtained data points, and using the model curve to obtain a gradation-correction curve for calibrating the printing process, where it is sufficient to use only patches obtained by filling every pixel in a patch with a same recording level.

Calibration of a multilevel inkjet process

Printing masters are produced by use of an inkjet printing system. The smallest halftone dot size which can be printed by the inkjet printing system is larger than the size of a pixel of the recording grid defined by the addressability of the printing device. The error diffusion algorithm is especially adapted to make use of the high addressability of the recording system. Using a sub-dot phase modulated error diffusion halftoning algorithm allows for the distance between the halftone dots to be modulated in much smaller increments than the size of the halftone dots themselves. Results can be further improved by dynamically influencing the threshold value in the error diffusion algorithm in accordance with previous output quantisation determinations. Variable coverage percentage of the pixels can be taken into account. The method can be extended to multilevel systems.

Growing community of inventors

Duffel, Belgium

Koen Vande Velde