Yarn segmentation for Dorian. This is ITK code, tested against ITK 3.20, which must be built with REVIEW ON, as that is where the marker based watershed lives. There is no command line argument checking, so it will crash if things are wrong. 2D, unsigned char images are assumed. Input is the filtered yarn image and the skeleton image in which the approximately horizontal skeletons line up with the dark parts of the filtered image.