  A uniform distribution of the image force field around the object fasts the
convergence speed of the segmentation process. However, to achieve this aim, it
causes the force constructed from the heat diffusion model unable to indicate
the object boundaries accurately. The image force based on electrostatic field
model can perform an exact shape recovery. First, this study introduces a
fusion scheme of these two image forces, which is capable of extracting the
object boundary with high precision and fast speed. Until now, there is no
satisfied analysis about the relationship between Snakes and Geometric Active
Contours (GAC). The second contribution of this study addresses that the GAC
model can be deduced directly from Snakes model. It proves that each term in
GAC and Snakes is correspondent and has similar function. However, the two
models are expressed using different mathematics. Further, since losing the
ability of rotating the contour, adoption of level sets can limits the usage of
GAC in some circumstances.
