Skip to main content

Efficient Painting & Enhancement of Hand-drawn Cartoon Animations

Final Report Summary - TOONPAINT (Efficient Painting & Enhancement of Hand-drawn Cartoon Animations)

The research objectives of TOONPAINT project was:

(1) to develop speed-up techniques which allow significant reduction of computational overhead while retain the advantages of the LazyBrush algorithm developed during the previous IEF project CARTOON; and
(2) to enable artists to produce more visually attractive content close to computer-generated imagery with the simplicity and expressiveness of the traditional animation.

In addition to research objectives, the aim of TOONPAINT was also to establish tight cooperation with the industry, improve publishing skills, and encourage formation of a new research group as well as search for funding to support future research activities.

An extension of Boykov-Kolmogorov's max-flow / min-cut algorithm has been developed that allows significant speed-up and reduction of memory bandwidth when computing maximum flows on graphs with grid-like topologies (such as graphs used in LazyBrush algorithm). It enables 3- to 9-fold speed-up and 3 to 12 times higher grid resolutions compared to the state-of-the-art solutions. The algorithm is described in the paper 'Cache-efficient graph cuts on structured grids' that was accepted as a full paper for a premier event in computer vision field: CVPR 2012 (Providence, Rhode Island, USA, 16 - 21 June 2012). It has been published by the IEEE in Proceedings of the 25th Conference on Computer Vision and Pattern Recognition. The invention was protected by US patent application: 'Optimising computation of minimum cut in graphs with grid topology' (No. 13/226,109, 6 September 2011) and a software library called 'GridCut' was released (1 June 2012) under a license allowing usage for non-profit purposes as well as commercial use.

A new texture mapping algorithm and subsequent post-processing operations have been developed that enable simulation of CG-like effects entirely in the 2D domain without necessity to create proxy 3D geometry. This new approach has been described in the paper 'TexToons: Practical texture mapping for hand-drawn cartoon animations' that was accepted as a full paper for NPAR 2011 (Vancouver, British Columbia, Canada, 7 - 11 August 2011) a premier event in the field of non-photorealistic animation and rendering, was published by the ACM in Proceedings of the 9th International Symposium on Non-Photorealistic Animation and Rendering, and won the Best Paper Award (animation).

A new Cartoon Processing Group was established within the Department of Computer Graphics and Interaction, FEE, CTU in Prague which initiated tight cooperation with industrial partners: Anifilm studio in Prague, Disney Research Zurich, and Walt Disney Animation Studios. A book chapter titled: 'Computer-assisted repurposing of existing animations' was written containing succinct description of algorithms developed within the research objectives of CARTOON and TOONPAINT projects.