Recently, there has been a reinvestigation of the use of local statistics by the image segmentation community in a variational framework. Locality is generally defined by means of an isotropic spatial kernel. These recent studies show a better behavior of local models on images with strong intensity inhomogeneities. Thus local segmentation models have become very popular. Very little work, however, has been carried out to address the problem of the choice of the local kernel's scale (or bandwidth). The present contribution falls within this context. Specifically, we investigate the problem of the estimation of a single scale (i.e. pixel independent) for local parametric region segmentation models. The approach is generic and straightforward. The method is demonstrated on synthetic and realistic simulations of ultrasound images with intensity inhomogeneities.