Séminaire de l'équipe A3SI du LIGM

Le dernier séminaire de l'équipe A3SI du LIGM (unité mixte de recherche de l'Université Paris Est) a eu lieu le mercredi 5 septembre à ESIEE Paris.

Deux exposés :

Stochastic geometry, topological and experimental
Herbert Edelsbrunner
IST Austria

Abstract: We study classical questions in stochastic geometry, such as the expected density of p-simplices in the Delaunay mosaic of a Poisson point process in d-dimensional Euclidean space.  Using a discrete Morse theory approach, we distinguish between critical and non-critical of the radius function and determine their expected densities dependent on a radius threshold.  We generalize the analytic results to weighted Delaunay mosaics and to order-k Delaunay mosaics, and we present experimental result for wrap complexes and for weighted Voronoi tessellations.

Hierarchical segmentation in a directed graph setting
which optimizes a graph cut energy
Krzysztof Ciesielski
West Virginia University

Abstract: There are several well known segmentation algorithms which outputs optimize the Lp norms of associated graph cuts. However, so far, such optimizations were restricted only to the cases, when graphs associated with the images were undirected graphs. In this talk, we discuss the situation when such optimization can be extended to directed graphs setting. This facilitates an incorporation of image orientedness properties into the segmentation process. Moreover, we describe how this oriented set-up can be efficiently applied to the multi-object segmentation, when the inclusions/disjointness hierarchy among the objects is known.