Curvature Correlograms for Content Based Retrieval of 3D Objects G. Antini, S. Berretti, A. Del Bimbo, and P. Pala Dipartimento di Sistemi e Informatica, Universit` a degli Studi di Firenze, via S.Marta 3, 50139 Firenze, Italy {antini, berretti, delbimbo, pala}@dsi.unifi.it Abstract. Along with images and videos, 3D models have raised a certain inter- est for a number of reasons, including advancements in 3D hardware and software technologies, their ever decreasing prices and increasing availability, affordable 3D authoring tools, and the establishment of open standards for 3D data inter- change. The resulting proliferation of 3D models demands for tools supporting their effective and efficient management, including archival and retrieval. In order to support effective retrieval by content of 3D objects and enable retrieval by object parts, information about local object structure should be com- bined with spatial information on object surface. In this paper, as a solution to this requirement, we present a method relying on curvature correlograms to perform description and retrieval by content of 3D objects. Experimental results are presented both to show results of sample queries by content and to compare—in terms of precision/recall figures—the proposed solu- tion to alternative techniques. 1 Introduction Beside image and video databases, archives of 3D models have recently gained in- creasing attention for a number of reasons: advancements in 3D hardware and software technologies, their ever increasing availability at affordable costs, and the establishment of open standards for 3D data interchange (e.g. VRML, X3D). Three-dimensional acquisition of a real-world object, capturing both object geom- etry and its visual features (surface color and texture), can be achieved through many different techniques, including CAD, 3D laser scanners, structured light systems and photogrammetry. Thanks to the availability of these technologies, 3D models are be- ing created and employed in a wide range of application domains, including medicine, computer aided design and engineering, and cultural heritage. In this framework the development of techniques to enable retrieval by content of 3D models assumes an ever increasing relevance. This is particularly the case in the fields of cultural heritage and historical relics, where there is a growing interest in solu- tions enabling preservation of relevant artworks (e.g. vases, sculptures, and handicrafts) as well as cataloguing and retrieval by content. In these fields, retrieval by content can be employed to detect commonalities between 3D objects (e.g. the “signature” of the artist) or to monitor the temporal evolution of a defect (e.g. the amount of bending for wooden tables). F. Roli and S. Vitulano (Eds.): ICIAP 2005, LNCS 3617, pp. 859–866, 2005. c  Springer-Verlag Berlin Heidelberg 2005