Detecting F-formations as dominant sets

The first step towards analysing social interactive behaviour
in crowded environments is to identify who is interacting
with whom. This paper presents a new method for detecting
focused encounters or F-formations in a crowded, reallife
social environment. An F-formation is a specific instance
of a group of people who are congregated together with the
intent of conversing and exchanging information with each
other. We propose a new method of estimating F-formations
using a graph clustering algorithm by formulating the problem
in terms of identifying dominant sets. A dominant set
is a form of maximal clique which occurs in edge weighted
graphs. As well as using the proximity between people, body
orientation information is used; we propose a socially motivated
estimate of focus orientation (SMEFO), which is calculated
with location information only. Our experiments show
significant improvements in performance over the existing
modularity cut algorithm and indicates the effectiveness of
using a local social context for detecting F-formations.