Agfa Graphics Nv

Agfa Gevaert Nv

Agfa-gevaert

Luc Minnebo

Paul A Delabastita

Koen Vande Velde

Koen Van De Velde

Kris Vangeel

Wim Helsen

Erik Van Geel

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

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

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.

Sub-dot phase modulation for computer to plate inkjet system

A multi-level printing process using a printer by converting electronic page data to multi-level bitmap data with a specific number of gradation levels Nlev at a specified spatial resolution higher than that of the printer; converting the multi-level bitmap data to a lower spatial resolution; reducing the number of gradation levels by a processing technique to some lower number Nlevp giving a second multi-level bitmap; and printing the multi-level output bitmap by a printer having at least Nlevp different gradation levels at a single pixel location.

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Brasschaat, Belgium

Luc Minnebo