Séance Séminaire

Séminaire de Probabilités et Statistique

Statistical models for the evolution of facial curves.

We present statistical models, based on Gaussian Processes, for the study of the evolution of facial curves. Evolution can be modelled viewing time as a linear, continuous variable, i.e., one curve that is gradually changing in a particular situation. Or it can play the role of evolutionary time, where branching points in the evolution can occur: ancestors diverging into multiple daughters. Two applications are studied: the evolution of the shape of the lips during the performance of an emotion (linear evolution) and the evolution of nose shape within and between ethnic groups (phylogenetic evolution). The facial images available are in the form of three-dimensional point clouds which characterize each facial surface. Each face is represented by around 100,000 points. Anatomical curves are studied to provide a rich characterization of the full anatomical surface.