Geometric shape priors for region-based active contours

In this paper, we present a novel approach for incorporating geometric shape priors in region-based active contours in order to provide more robustness to clutter, noise and occlusions. We define shape descriptors based on Legendre moments and embed them in a recent Eulerian formulation of region-based active contours, which enables a rigorous mathematical treatment. An evolution equation that minimizes a function of the distance between the active contour and a reference shape is derived. Experimental results show the ability of the geometric shape prior to constrain an evolving curve to resemble a target shape. We finally introduce the new shape prior into a two-class segmentation functional and show its benefits on segmentation results, in presence of occlusions and clutter.