View larger version (304K)

Figure 23a.  Visualization with volume rendering. (a) Object-based volume-rendered image demonstrates bone and soft-tissue structures (muscles) that had been detected earlier as separate fuzzy connected objects in a 3D craniofacial CT scene. The skin is essentially "peeled away" because of its weak connectedness to muscles. (b) Scene-based volume-rendered version of the scene in a was acquired with use of the opacity function (cf Fig 13) separately for bone and soft tissue. The skin has become indistinguishable from muscles because they have similar CT numbers and hence obscures the rendition of the muscles.