Figure 6.

Images illustrating how the optimal local directions were obtained for one example voxel within the GWB, and width computation at the given voxel v_i,LGWB. (A,B) Method to find the corresponding voxels on the GM (v_i,LGM) and the WM (v_i,LWM), through iteratively searching the neighborhood and finding the voxels with smallest and largest potential values. (C) An illustrative path from GM to WM for the given voxel v_i,LGWB. (D) The way to compute the width value at v_i,LGWB, according to its v_i,LGM and v_i,LWM. For the rest of the voxels within GWB (with yellow base color in D), the width values can be obtained by the following procedures.