Multilevel halftoning applied to achromatic inks in multi-channel printing
2014 (English)In: Abstracts from 41st International research conference of iarigai: Advances in Printing and Media Technology, Print and media research for the benefit of industry and society, 2014, 25-25 p.Conference paper (Other academic)
Printing using more than four ink channels visually improves the reproduction. Nevertheless, if the ink layer thickness at any given point exceeds a certain limit, ink bleeding and colour accuracy problems would occur. Halftoning algorithms that process channels dependently are one way of dealing with this shortcoming of multi-channel printing. A multilevel halftoning algorithm that processes a channel so that it is printed with multiple inks of same chromatic value was introduced in our research group. Here we implement this multilevel algorithm using three achromatic inks – photo grey, grey, black – in a real paper-ink setup. The challenges lay in determining the thresholds for ink separation and in dot gain compensation. Dot gain results in a darker reproduction and since it originates from the interaction between a specific ink and paper, compensating the original image for multilevel halftone means expressing dot gain of three inks in terms of the nominal coverage of a single ink. Results prove a successful multilevel halftone implementation workflow using multiple inks while avoiding dot-on-dot placement and accounting for dot gain. Results show the multilevel halftoned image is visually improved in terms of graininess and detail enhancement when compared to the bi-level halftoned image.
Place, publisher, year, edition, pages
2014. 25-25 p.
Multilevel halftoning, multi-channel printing, dot gain compensation, graininess
IdentifiersURN: urn:nbn:se:liu:diva-112265OAI: oai:DiVA.org:liu-112265DiVA: diva2:764691
41st International research conference of iarigai, 7-10 September 2014, Swansea, Wales, UK