Invariant-based data model for image databases - Image Processing, 1998. ICIP 98. Proceedings. 1998 International Conference on

W e describe a new invariant-based data model for image databases under our approach fo r shape-based retrieval. The data model relies on contours description of the image shape, and emphasizes the use of invariants. Efjicient indexing is based on geometric invariant features, while semi-local multi-valued invariant signatures are used for ranking the answers. The advantages of the proposed approach are its ability to retrieve images in situations in which part of the shape is missing (i.e., in case of occlusion or sketch queries), its ability to handle images distorted b y different viewpoint transformations, and its ability t o flexibly answer queries based on logical or shape descriptions (query b y example), or on combination of both. The approach also handles sketch based queries. We implemented our data model in an object oriented database system with a SQL-like user interface. The paper presents experimental results demonstrating the effectiveness of the proposed approach.