  In this paper we propose a high-order accurate scheme for image segmentation
based on the level-set method. In this approach, the curve evolution is
described as the 0-level set of a representation function but we modify the
velocity that drives the curve to the boundary of the object in order to obtain
a new velocity with additional properties that are extremely useful to develop
a more stable high-order approximation with a small additional cost. The
approximation scheme proposed here is the first 2D version of an adaptive
"filtered" scheme recently introduced and analyzed by the authors in 1D. This
approach is interesting since the implementation of the filtered scheme is
rather efficient and easy. The scheme combines two building blocks (a monotone
scheme and a high-order scheme) via a filter function and smoothness indicators
that allow to detect the regularity of the approximate solution adapting the
scheme in an automatic way. Some numerical tests on synthetic and real images
confirm the accuracy of the proposed method and the advantages given by the new
velocity.
