Skeletal Structures Silvia Biasotti1, Dominique Attali2, Jean-Daniel Boissonnat3,Herbert Edelsbrunner4,GershonElber5, Michela Mortara1, Gabriella Sanniti di Baja6, Michela Spagnuolo1, Mirela Tanase7,andRemcoVeltkamp7 1 CNR. - Ist. di Matematica Applicata e Tecnologie Informatiche, Genova, Italy. silvia.biasotti,michela.mortara,
[email protected] 2 LIS-CNRS, Domaine Universitaire, BP 46, 38402 Saint Martin d’H`eres, France.
[email protected] 3 INRIA, 2004 Route des Lucioles, BP 93, 06904 Sophia-Antipolis, France.
[email protected] 4 Department of Computer Science, Duke University, Durham, and Raindrop Geomagic, Research Triangle Park, North Carolina, USA.
[email protected] 5 Technion, Israel Institute of Technology, Israel.
[email protected] 6 CNR - Ist. di Cibernetica “E. Caianello”, Pozzuoli, Napoli, Italy.
[email protected] 7 Universiteit Utrecht (UU), The Netherlands.
[email protected] Shape Descriptors are compact and expressive representations of objects suit- able for solving problems like recognition, classification, or retrieval of shapes, tasks that are computationally expensive if performed on huge data sets. Skele- tal structures are a particular class of shape descriptors, which attempt to quantify shapes in ways that agree with human intuition. In fact, they repre- sent the essential structure of objects and the way basic components connect to form a whole. In the large amount of literature devoted to a wide variety of skeletal structures, this Chapter provides a concise and non-exhaustive introduction to the subject: indeed the first structural descriptor, the medial axis, dates back to 1967, which means forty years of literature on the topic.