Talk: Clemens Kiristis

On Wednesday, Oct. 29, 15 ct. Clemens Kiristis from the University of Vienna will give a talk on "Optical Flow on Evolving Surfaces".

Location: MIC-Arena, Maria-Goeppert-Str. 3, 23562 Lübeck

Title: Optical Flow on Evolving Surfaces

Abstract: We present two approaches for the estimation and analysis of endodermal cell motion from volumetric time-lapse (4D) microscopy images. In both approaches we avoid computational challenges by exploiting the fact that during early embryogenesis endodermal cells can be regarded as sitting on a 2D surface. Consequently, we formulate the problem of estimating their velocities as a Tikhonov-regularized optical flow problem on a surface. First, we assume the surface to be a static sphere and study different regularization functionals as well as vector field decomposition models, which are easily realized by expanding vector fields in tangent vector spherical harmonics. In the second approach we try to model the endoderm layer more accurately as an evolving surface. This necessitates the extension of existing optical flow models. In particular we generalize the spatiotemporal regularization model by Weickert and Schnörr (2001) to the new setting, show its wellposedess, and present experimental results on the aforementioned data.