Welcome at the "Welfenlab"

Institut für Mensch-Maschine-Kommunikation
FG Graphische Datenverarbeitung

Leibniz Universität Hannover - Welfengarten 1 - 30167 Hannover
Phone: (+49) 511.762 - 2910
Fax: (+49) 511.762 - 2911

Tactile Perception of Textiles in a Virtual-Reality System

Dennis Allerkamp

Während seiner Arbeit im HAPTEX-Projekt und später in seiner Dissertation hat Dennis Allerkamp hier im Welfenlab die haptische Wahrnehmung des Menschen insbesondere für Anwendungen in virtuellen Umgebungen erforscht. Dabei entstanden sowohl eine haptische Simulation der Oberfläche von Textilien, als auch ein haptisches Display, das die simulierten Tastimpulse für einen Menschen fühlbar machen kann.

In seinem jetzt erschienenen Buch "Tactile Perception of Textiles in a Virtual-Reality System" beschreibt er ein solches System komplett von den wahrnehmungspsychologischen und biologischen Grundlagen bis hin zu der technischen Umsetzung und experimentellen Ergebnissen.

Das Buch erscheint in der COSMOS-Reihe des Springerverlags unter der ISBN 978-3-642-13973-4.

Keynote Lecture auf der CGI 2010

Am 10. Juni hielt Prof Wolter eine Keynote Lecture auf der CGI 2010 in Singapur

Download der Folien

Shape and Image Cognition, Construction and Compression via Tools from Differential Geometry

We shall describe how concepts from differential geometry especially from Riemannian geometry have been providing powerful tools creating major advances in geometric modeling, geometry processing and image analysis dealing with the topics presented in the title of this address. This talk includes a retrospective compiling contributions of the author`s works showing how concepts from local and global differential geometry have introduced new methods into geometric modeling and shape interrogation and classification finally ending with modern state of the art research on geometry processing and image processing.

We start sketching early contributions on curvature analysis of surface constructions and surface intersections. Next we focus on cut loci, the medial axis and its inverse in Euclidean and Riemannian worlds. This work starts with basic medial axis results presented by the the author in the early nineties when the medial axis was not considered as a main stream subject in the respective scientific communities. Those results state: The Medial Axis Transform can be used to reconstruct, modify and design a given shape ("Shape Reconstruction Theorem"). Under some weak assumptions the medial axis contains the essence of the topological shape of the geometric object as it is a deformation retract of the given shape ("Topological Shape Theorem"). Therefore the medial axis contains the homotopy type of the given shape.

We present recent results showing how geodesic Voronoi diagrams, geodesic medial axis and its inverse can be computed in 3d- or higher dimensional Riemannian spaces. The "medial axis inverse" allows to construct a medial modeller providing efficient features for shape optimization with respect to shape dependent mechanical properties.

A major part of this talk starting with works in the nineties at the author`s lab is dedicated to discussing how "efficient finger prints" useful for indexing and clustering digital data collections can be derived from spectra of Laplace operators being naturally associated with geometric objects such as surfaces and solids as well as (coloured) images including medical 2d- and 3d-images. Recently the latter works obtained particular attention in the area of medical imaging.