In this paper, a partial matching problem among pictures composed of multiple closed regions is described by taking a sequence of animation pictures as an example. Closed regions including holes and islands are analyzed and described by a set of edges specified by angles, positions, trailing and leading vectors. Then, a kind of relaxation methods is used to make partial matchings between the preceding picture (template) and the current picture through global and local matching processings. This method was applied to a sequence of cel animation pictures drawn manually, and as the results, more than half of closed regions included in pictures were identified correctly.

A fast identifying method of animation line drawings composed of some ten closed regions is described by the use of spatial location and adjacent relation among closed regions contained in successive two frames of the line drawings. The method consists of global and local matching. The global matching identifies closed regions which change slightly in size and shape as a set of three closed regions in each of successive two frames by the use of a relaxation method. In the local matching, closed regions identified in the global matching are taken as seeds around which new interpritations may grow, and unidentified closed regions which are adjacent to the seeds and have similar location relation are identified by taking vectors drawn between centroids of closed regions as parameters. The mechod is applied to a series of sixteen line drawings, and all the closed regions contained in the line drawings are correctly identified excepting closed regions newly appeared in successive two frames.

A fundamental study for labeling and painting of line drawings is described, and its applications to an animation cel and alphabet are exemplified. Multiple closed regions included in binary line drawings are extracted, and they, both enclosed by image pixels and by non-image pixels, are labeled from the outermost boundary into inner boundaries. After that, a set of these labeled regions is transformed into a simple string by using inclusion relation and disjoint relation defined among them. In the method, the contour of every closed region is automatically traced, and the coordinates of the traces points are stored in the memory of a computer. Inclusion relation and disjoint relation among multiple closed regions are obtained by comparing the numbers (areas) of image pixels and non-image pixels.