Iterative Shape Averging USAGE:
/build/cmtk-1dBBe8/cmtk-3.3.1p2+dfsg/debian/cmtk/usr/lib/cmtk/bin/iterative_shape_averaging
referenceImagePath imagePath1 imagePath2 ...
where the first argument is the path of the initial reference image and
the remaining arguments are the remaining images in the set to be averaged.
Please make sure the initial reference image is not also listed in the
list of remaining images.