Automatic cel painting in computer-assisted cartoon production using similarity recognition

The task of painting each cel of an animated sequence has always been a tedious work using traditional methods. In order to simplify and speed up the process, the development of an automatic cel painting system is desired. This paper presents a method for assisting the production of cartoon animation using computers in order to reduce the production expense and to improve the overall quality. It signals a great improvement in the working environment where 2-D animation is produced. The basic idea of our automatic cel painting mechanism is to extract both statistical and topological features of regions from input animation drawings, and to search for similar corresponding regions in the previous drawing. If the similarity measures are within the accepted thresholds, the corresponding colour will be inherited. A new integrated labelling algorithm constructing statistical region and topological graph features is proposed. Furthermore, a similarity measure of regions is defined and an algorithm of partial matching of attribute graphs is presented. The experimental result shows the feasibility and practicability of the proposed approach. © 1997 John Wiley & Sons, Ltd.