Using a prototype voxel for visualizing volumetric data
William C. Buckalew · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1993
We present a method for visualizing volumetric data such as NMI or CAT-scan data that makes use of a data structure called the prototype voxel to create images very quickly on common workstation screens. The algorithm speeds up the standard process of casting rays through the volume data by precomputing a great deal of direction and interpolation information, assuming that all voxels are the same size and shape (which is normally the case for medical data sets). As rays are cast, this information, stored in the prototype voxel, is merely looked up when needed rather than being recomputed repeatedly. The prototype voxel must be computed only once for each data configuration; subsequent data sets which use the same size and shape of voxel can use the same prototype voxel information to speed rendering. This algorithm trades memory for speed: it uses 20 to 50 megabytes of memory (already becoming commonly available in modern workstations) for its speed improvements.