An Insight Toolkit (ITK) processing framework for simultaneous segmentation of multiple objects using
active contours without edges is presented in this paper. These techniques are also popularly referred to
as multiphase methods. Earlier, we had an implemented the Chan and Vese [1] algorithm that uses level-
sets to accomplish region segmentation in images with poor or no gradient information. The current
work extends that submission to use multiple level sets that evolve concurrently. The basic idea is to
partion the image into several sets of piecewise constant intensity regions. This work is in contrast to
the level-set methods currently available in ITK which necessarily require gradient information and also
necessarily segment a single object-of-interest. Similar to those methods, the methods presented in this
paper are also made efficient using a sparse implementation strategy that solves the contour evolution
PDE at the level-set boundary. This work does not introduce any new filter but extends the earlier
submitted to filters to process multiple objects. We include 2D/3D example code, parameter settings and
show the results generated on a 2D cardiac image.