Agfa Gevaert Nv

Rene Govaert

Paul A Delabastita

Jacobus Herman Bosschaerts

Dirk De Baer

A method for making a lithographic printing plate from an original containing multiple tones comprising the steps of frequency modulation screening the multiple image to obtain screened data representing tones of the multiple tone image in terms of halftone dots; reproducing the halftone dots on a lithographic printing plate precursor having a surface capable of being differentiated in ink accepting and ink repellant areas upon scanwise exposure and an optional development step, by means of a scanwise exposure, wherein the scanwise exposure for rendering a halftone dot is intensity modulated.

Intensity modulated stochastic screening for preparing a lithographic

In order to achieve a larger color gamut, more colorants are used than the classical three chromatic colors cyan, magenta and yellow. The use of extra process colors, such as red or orange, green and blue, poses extra requirements on the screening process or on the color separation process. A method is described in which optimal color rendering is achieved by use of maximum three chromatic colorants at the same place only. In one embodiment particular sets of three chromatic colorants each cover color sub-gamuts which are disjunctive, allowing each input color to be located within one color sub-gamut. A set comprises no complementary colors.

High fidelity color rendering method avoiding moire problems

A method for generating a screened reproduction of a multiple tone image comprising the steps of frequency modulation screening the multiple tone image to obtain screened data representing tones of the multiple tone image in terms of halftone dots, reproducing the halftone dots on an imaging element by means of a scanwise exposure, characterized in that the scanwise exposure for rendering a halftone dot is time modulated.

Time modulated stochastic screening

A method for generating a screened reproduction of a multiple tone image comprises the steps of frequency modulation or stochastic screening the multiple image to obtain screened data representing tones of the multiple tone image in terms of halftone dots; reproducing the halftone dots on an imaging element by means of a scanwise exposure, wherein the size or composition of the halftone dot is modulated, by varying the number of microdots (or rels) composing a halftone dot.

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Kapellen, Belgium

Rene Govaert