MultiDot - nowa idea rastrowania AM

• Autorzy: Kunstetter A.

Warianty tytułu

EN

MultiDot - the new AM screening concept

• Języki publikacji: PL

Abstrakty

EN

Screening technology let reproduce continuous tone images using bilevel printing method (as f.e. offset). Some properties of human eye allows the correct reception of the continuous tone image. One have to remember, that tonal value (caused by surface covered by printing elements only) existing on the printing plateis not the same as the one present on the printout. In offset printing technology the difference between tonal value on the printing plate and on the printout is provoked by two different phenomenons: one is the DotGain, while the other is caused by driving the ink out by dampening solution. The DotGaineffecthas 3 mainreasons: – spilling out of the ink on the printedsurface, – deformation of transfer medium (f.e. offset blanket) – present only when indirect printing technology is in use – “shadow” of the printing inklayer, ... and iswelldefined and known. The mutual (the ink and the water/dampening solution) influence is very difficult to predict using mathematic formulas. We can observe, that (because of the DotGain effect) there are some areas not covered by ink, but absorbing the light as they would be – so it can be a base for some ink saving – if the effect would be used properly. However the FM screening has significant DotGain effect (so ink saving should be noticeable), it demonstrates lot of disadvantages: less print stability, unevenly flat areas and many, many others. To fulfill some expectations the new AM screening was developed (and patented). It was named MultiDot and is based on multi-cluster principle, where – what’s important – single clusters have different size and shape. Optimal shape and tonal function caused, that newly developed screening concept let the user receive stable, rich in details and Moire free images with significant ink-saving capabilities. The other aspect of using MultiDot screening structure is to prevent prints against illegal copying and allowing the user to confirm (or deny) the authenticity of certain printouts or goods – this functionality is called MultiDot Security and will be a subject of another article.

Słowa kluczowe

PL

raster; farba; przyrost punktu rastrowego; modulowanie amplitudowe; system MultiDot

EN

raster; paint; amplitude modulation; MultiDot system

• Wydawca: Centralny Ośrodek Badawczo-Rozwojowy Przemysłu Poligraficznego
• Czasopismo: Acta Poligraphica
• Rocznik: 2018
• Tom: Vol. 11
• Strony: 23--29
• Opis fizyczny: Bibliogr. 8 poz., rys.

Twórcy

autor

Kunstetter A.

• Heidelberg Polska

Bibliografia

• 1. Boff K. R., Kaufmann L., Thomas P., Handbook of Perception and Human Performance vol. 1. New York–Chichester–Brisbane–Toronto–Singapore 1986.
• 2. Ulichney R., Digital Halftoning. MIT Press, Cambridge/Mass. 1987.
• 3. Venkata Damera N., Evans B. L., FM halftoning via block error diffusion. International Conference On Image Processing, vol. 3. Thessaloniki 2001.
• 4. Wadle H., An Introduction to Screening Technology, Expert Guide. Heidelberger Druckmaschinen AG., Heidelberg 2007.
• 5. Aijazi A.T., Hybrid Color Halftoning, Master thesis. Linköping University - Department of Science and Technology, Linköping 2010.
• 6. Žitinski P. E., Halftoning for Multi-Channel Printing, Linköping University - Department of Science and Technology, Linköping 2014.
• 7. US Patent nr US 8,576,449 B2 Nov 2013. Parametrically Controlled halftone Spot Function for an Irregular Halftone Grid.
• 8. US Patent nr US 2006/0002603 A1 Jan 2006. Optical Proximity Correction in Raster scan printing based on corner matching templates.

Uwagi

PL

Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2018).