Abstract
First an analysis on geometrical properties of local symmetry of planar shapes is given. Based on the analysis, a new shape descriptor called the chain of circles (CoCs) is defined herein. Then it is shown that the CoCs representation obtained can be controlled in a hierarchical manner which appeals to intuition. The coarse-to-fine hierarchy makes matching of shapes possible with less computational complexity and greater robustness to noise, rotation and scaling of shapes. The dissimilarity vector calculated in the matching may facilitate the searching process in the digital library. The capability of the suggested method is shown by matching several non-formal shapes such as map images.
