The medial axis is susceptible to surface noise, which results in spurious branches. Additionally bifurcations points of the medial axis may have to be merged to produce the desired object characterization (i.e. four pore channels meeting at a nodal pore may appear as 2 three channel bifurcations in the medial axis.) This option provides the facility to modify the medial axis to account for these tendencies. The medial axis is input in voxel-list format. The modified axis can be output in any of the three formats.