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CACE Model

We propose a novel active contour model by incorporating particle based electronstatic interactions into the geometric active contour framework. It is an extension of the very recent work by Jalba et al. (T-PAMI 26(10)) on a particle deformable model, which is based on charged particle dynamics, founded on electrostatics and particle movements, and called the Charged Particle Model (CPM). CPM has been demonstrated to capture object boundaries over the entire image with a set of free charged particles. While an initialization step is still required, it is certainly less pivotal than in the contour model. However, this particle model a) can not guarantee continuous and closed final contours, b) does not stabilise as there is no effective stopping term, and c) is computationally intensive.

This new framework by introducing particle dynamics into active contour propagation, resulting in a Charged Active Contour based on Electrostatics (CACE) model incorporates the advantages of both contour and particle based models. CACE can detect object boundaries via contour propagation under the influence of a bi-directional force field that simulates the electrostatic interaction between an image-derived point charge field and a charged contour. In other words, the force consists of boundary attraction and competition terms that lead the contour towards object boundaries. CACE is much faster and more efficient in convergence than CPM. More importantly, it eliminates CPM's tendency to sometimes result in open contours. CACE also has significant advantages over the geodesic and GVF geodesic snakes in that it is more robust to initial placement and is able to handle objects of more complicated topology, e.g. those with narrow parts.

This research is a further development of recent model, named Charged Active Contour Model (CCM), in which also uses pariticle dynamics. However, it does not include the boundary competition forces. More details of the CCM can be found here.

Example results:

Geodesic Snake
GVF snake
CPM model
Proposed CACE model



Xianghua Jason Xie, x.xie at swansea.ac.uk, Last modified on 02 October 2007 at 12:00. ©2007 University of Wales Swansea. University of Bristol Free Hit Counter