ACTIVE-REGION MODELS FOR SEGMENTING TEXTURES AND COLORS

This paper describes a new region-growing method that uses a closed snake driven by a pressure force that is a function of the statistical characteristics of image data. This statistical snake expands until its elements encounter pixels that lie outside user-defined limits relative to a seed region; when these limits are violated the pressure force is reversed to make the model contract. Tension and stiffness forces keep the boundary of the region model smooth, and a repulsion force prevents self-intersection. Boundary elements can be inserted and deleted in response to complexity changes, and the tension and stiffness parameters can be adjusted to preserve the energy balance of the changing model. Statistical snakes have been used to segment a variety of composite textures; they have also been used to track rigid coloured regions in real-time video by modifying the energy formalism to produce affine motion.