Active contours is a popular technique for image segmentation.
However, active contour tend to converge to the
closest local minimum of its energy function and often requires
a close boundary initialization. We introduce a new
approach that overcomes the close boundary initialization
problem by reformulating the external energy term. We treat
the active contour as a mean curve of the probability density
function p(x). It moves to minimize the Kullback-Leibler
(KL) divergence between p(x) and the probability density
function derived from the image. KL divergence forces p(x)
to cover all image areas and the uncovered areas are
heavily penalized, which allows the active contour to go
over the edges. Also we use deterministic annealing on the
width of p(x) to implement a coarse-to-ne search strategy.
In the limit, when the width of p(x) goes to zero, the
KL divergence function converges to the conventional external
energy term (which can be seen a special case) of acti...
Andriy Myronenko, Xubo B. Song