Multiscale snake algorithm based on improved external force

The magnitude-only external force is modified by integrating direction information explicitly and a new snake model is derived. The new snake model can greatly eliminate the disturbance of false strong edges. Based on dynamic programming approach to snake model, a wavelet-based multiscale algorithm is proposed. Combined with Mallat's wavelet-based edge detection theory, the proposed multiresolution algorithm can greatly decrease the amount of computation, become more flexible in selecting filter than continuation method, and has less initial position sensitivity and parameter sensitivity, which enlarges the target capturing region and makes the setting of parameters simplified.