Fig. 3.

Hole filling using sticks is demonstrated. The dimensionality is reduced to allow for illustration. A filled voxel is denoted with an “F,” and a hole voxel is denoted with an “H.” (a) A hole we wish to fill is at the center of the image, marked with a bolded “X”; (b) the stick is traversed along the dashed line to find a pair of voxels on opposite sides of the hole, marked by empty bolded circles; (c) the voxel intensity is linearly interpolated between the pair of voxels with the shortest distance between them (i.e., number of sticks is 1).