Combined Volume Registration and Visualization

We describe a method for combining and visualizing a set of overlapping volumetric data sets with high resolution but limited spatial extent. Our system combines the calculation of a registration metric with ray casting for direct volume rendering on the graphics processing unit (GPU). We use the simulated annealing algorithm to find a registration close to optimal and allow the user to closely monitor the optimization progress. The combined calculation reduces memory traffic, increases rendering frame rate, and makes possible interactive-speed, user-supervised, semi-automatic combination of many component volumetric data sets.