Multi-channel printing by orthogonal and non-orthogonal AM halftoning
2013 (English)In: Proceedings of 12th International AIC Colour Congress: Bringing Colour to Life, Newcastle, UK, 2013Conference paper (Refereed)
Multi-channel printing with more than the conventional four colorants brings numerous advantages, but also challenges, like implementation of halftone algorithms. This paper concentrates on amplitude modulated (AM) halftoning for multi-channel printing. One difficulty is the correct channel rotation to avoid the moiré effect and to achieve colour fidelity in case of misregistration. 20 test patches were converted to seven-channel images and AM halftoning was applied using two different approaches in order to obtain a moiré-free impression. One method was to use orthogonal screens and adjust the channels by overlapping the pairs of complimentary colours, while the second was to implement non-orthogonal halftone screens (ellipses). By doing so, a wider angle range is available to accommodate a seven-channel impression. The performance was evaluated by simulating misregistration in both position and angle for a total of 1600 different scenarions. ΔE values were calculated between the misregistered patches and the correct ones, for both orthogonal and non-orthogonal screens. Results show no visible morié and improvement in colour fidelity when using non-orthogonal screens for seven-channel printing, producing smaller colour differences in case of misregistration.
Place, publisher, year, edition, pages
Newcastle, UK, 2013.
multi-channel printing, AM halftoning, halftoning angle, non-orthogonal screen, moiré effect
IdentifiersURN: urn:nbn:se:liu:diva-107135OAI: oai:DiVA.org:liu-107135DiVA: diva2:722011
12th International AIC Colour Congress, 8-12 July 2013, Newcastle upon Tyne, UK
ProjectsColour Printing 7.0: Next Generation Multi-Channel Printing