Non-Photorealistic Computer Graphics Library

LazyBrush: Flexible Painting Tool for Hand-drawn Cartoons

Author(s): Daniel Sýkora, John Dingliana, Steven Collins.
Article: Computer Graphics Forum, Vol. 28, No. 2, pp. 599--608, 2009.
[BibTeX] [DOI]

Abstract:
In this paper we present LazyBrush, a novel interactive tool for painting hand-made cartoon drawings and animations. Its key advantage is simplicity and ?exibility. As opposed to previous custom tailored approaches [SBv05, QWH06] LazyBrush does not rely on style speci?c features such as homogenous regions or pattern continuity yet still offers comparable or even less manual effort for a broad class of drawing styles. In addition to this, it is not sensitive to imprecise placement of color strokes which makes painting less tedious and brings signi?cant time savings in the context cartoon animation. LazyBrush originally stems from requirements analysis carried out with professional ink-and-paint illustrators who established a list of useful features for an ideal painting tool. We incorporate this list into an optimization framework leading to a variant of Potts energy with several interesting theoretical properties. We show how to minimize it ef?ciently and demonstrate its usefulness in various practical scenarios including the ink-and-paint production pipeline.