Fig. 4. Cross sections through the density map (top row) and the segmented image (middle row) for the simulated sand media (left) and numerically generated glass bead packings (right). The numbers in the images denote the voxel sizes. In the first two rows, the images calculated with the voxel size of the tomography with X-rays from tubes or thermal neutrons, respectively, are shown. The last row gives the density map calculated with the highest resolution (1000³ voxels).