3 research outputs found
Curvature-based spectral signatures for non-rigid shape retrieval
The geometric properties of descriptors derived from the diusion geometry family have many valuable properties for shape analysis. These descriptors, also known as diusion distances, use the eigenvalues and eigenfunctions of the Laplace-Beltrami operator to construct invariant metrics about the shape. Although they are invariant to many transformations, non-rigid deformations still modify the shape spectrum. In this paper, we propose a shape descriptor framework based on a Lagrangian formulation of dynamics on the surface of the object. We show how our framework can be applied to non-rigid shape retrieval, once it benefits from the analysis and the automatic identification of shape joints, using a curvature-based scheme to identify these regions. We also propose modifications to the Improved Wave Kernel Signature in order to keep descriptors more stable against non-rigid deformations. We compare our spectral components with the classic ones and our spectral framework with state-of-the-art non-rigid signatures on traditional benchmarks, showing that our shape spectra is more stable and discriminative and clearly outperforms other descriptors in the SHREC’10, SHREC’11 and SHREC’17 benchmarks
Correspondence of three-dimensional objects
First many thanks go to Prof. Hans du Buf, for his supervision based
on his experience, for providing a stimulating and cheerful research environment
in his laboratory, for letting me participate in the projects that
produced results for papers, thus made me more aware of the state of the
art in Computer Vision, especially in the area of 3D recognition. Also for
his encouraging support and his way to always nd time for discussions,
and last but not the least for the cooking recipes...
Many thanks go also to my laboratory fellows, to Jo~ao Rodrigues, who
invited me to participate in FCT and QREN projects, Jaime Carvalho
Martins and Miguel Farrajota, for discussing scienti c and technical
problems, but also almost all problems in the world.
To all persons, that worked in, or visited the Vision Laboratory, especially
those with whom I have worked with, almost on a daily basis.
A special thanks to the Instituto Superior de Engenharia at UAlg and
my colleagues at the Department of Electrical Engineering, for allowing
me to suspend lectures in order to be present at conferences.
To my family, my wife and my kids