3D Computed Tomography reconstruction as well as 2D CT slices are displayed in grey-levels. The best grey-level resolution today is 16 bits, i.e. 65,536 different grey-levels. As with X-rays, grey-levels correspond to density in the material, thus making it possible to select a specific range of density value in the object (segmentation)

plaster

Plaster Sample

tn_wood3_3_1024x768_

Wood