Asymptotic Behavior of a Geman and McClure Discrete Model

In this paper we consider a class of discrete variational models derived from a theory of Geman and McClure (see [15]) and study their asymptotic behavior when their stepsize tends to zero. It is shown that a result of Γ -convergence toward a certain functional holds true if a characteristic parameter of these models obeys a well-defined dependence law upon the stepsize. Under this condition the Γ -limit is a modified form of the Mumford—Shah functional. Accepted 19 June 1998