Contrary to the vast majority of approaches to clustering, which view 
the problem as one of partitioning a set of observations into coherent 
classes, thereby obtaining the clusters as a by-product of the 
partitioning process, we propose to reverse the terms of the problem and 
attempt instead to derive a rigorous formulation of  the very notion of 
a cluster. In our endeavor to provide an answer to this question, we 
found that game theory offers a very elegant and general perspective 
that serves well our purposes.
Accordingly, we formulate the clustering problem as a non-cooperative 
"clustering game". Within this context, the notion of a cluster turns 
out to be equivalent to a classical equilibrium concept from 
(evolutionary) game theory. Applications to computer vision problems and 
generalizations of the proposed idea will be discussed.