Deformable prototypes for encoding shape categories in image databases

摘要

An image database search method is described that uses strain energy from prototypes to represent shape categories. Rather than directly comparing a candidate shape with all entries in a database, shapes are ordered in terms of non-rigid deformations that relate them to a small subset of representative prototypes. Shape correspondences are obtained via modal matching, a decomposition for matching, describing, and comparing shapes despite sensor variations and non-rigid deformations. Deformation is decomposed into an ordered basis of orthogonal principal components. This allows selective invariance to in-plane rotation, translation, and scaling, and quasi-invariance to affine deformations. Retrieval accuracy and stability are evaluated in experiments with 2-D image databases.