Efficient retrieval and spatial querying of 2D objects

Besides traditional applications (e.g., CAD/CAM and Trademark registry), new multimedia applications such as structured video, animation and MPEG-4 standard require the storage and management of well-defined objects. For efficient retrieval of 2D objects by shape, we propose three index structures on features that are extracted from the objects´ minimum bounding circles (MBC). A major observation is that those features are unique per object and can be utilized to filter out non-similar candidates. To evaluate our techniques, we conducted a simulation study on a database of 2D objects. The results show the superiority of our techniques as compared to a naive indexing (at least 40% improvement in I/O cost). We also identify one of the indexing structures as the superior one, independent of the size of the database and the number of vertices of the objects