High-speed computation of the Radon transform and backprojection using an expandable multiprocessor architecture

The accuracy and speed characteristics of implementations of several line integration models required for Radon (1917) transform (used for computed tomography image reconstruction) and backprojection computations are described and compared. The fixed-point number system used is evaluated by error comparisons to identical floating-point calculations. An expandable multiprocessor architecture for high-speed computation that has been realized as a prototype using commercially available digital signal processor (DSP) chips as the basic processing elements is described. The simulated performances of two popular DSP chips for this application are discussed and compared. Performance characteristics of the complete prototype hardware system are presented. The computational speed of a four-chip system is measured to be more than 190 times better than that of a Sun 3/160 with a math coprocessor. The architecture and prototype organization are not dependent on the DSP chip chosen, and substitution of the most up-to-date DSP chips can yield even better speed performance