Ein direktes Verfahren zur Segmentierung unstrukturierter Punktdaten und Bestimmung algebraischer Oberflächenelemente [Elektronische Ressource] / von: Marek Vančo

A Direct Approach for the Segmentation ofUnorganized Points and Recognition of SimpleAlgebraic SurfacesPhD ThesisM. VancoˇUniversity of Technology ChemnitzOctober 2002Ein direktes Verfahren zur Segmentierung unstrukturierterPunktdaten und Bestimmung algebraischer Oberflachenelemente¨Dissertationzur Erlangung des akademischen GradesDoktoringenieur(Dr.-Ing.)vorgelegtder Fakultat¨ fur¨ Informatikder Technischen Universitat¨ Chemnitzvon: Dipl.-Inf.(SK) Marek Vancoˇgeboren am: 6. Juni 1974in: BratislavaGutachter: Prof. Dr. Guido BrunnettProf. Dr. Beat D. Bruderlin¨Prof. Dr. Hans HagenChemnitz, 10. Oktober 2002AbstractIn Reverse Engineering a physical object is digitally reconstructed from a set ofboundary points. In the segmentation phase these points are grouped into subsets tofacilitate consecutive steps as surface fitting. In this thesis we present a segmentationmethod with subsequent classification of simple algebraic surfaces. Our method is di-rect in the sense that it operates directly on the point set in contrast to other approachesthat are based on a triangulation of the data set.The reconstruction process involves a fast algorithm for k-nearest neighbors searchand an estimation of first and second order surface properties. The first order segmen-tation, that is based on normal vectors, provides an initial subdivision of the surfaceand detects sharp edges as well as flat or highly curved areas.