Table 3.

Runtime comparison, in milliseconds, of different 3D interpolation implementations for reverse mapping operator without memory caching (GPU global), with linear texture cache (1D linear) and hardware accelerated interpolation using 3D texture. The GPU-accelerated implementation is about 40 times faster than CPU reference and gives identical results.

Method	CPU	GPU global	1D linear	3D texture
256 × 256 × 256	777	30	24	19
160 × 224 × 160	209	10.4	7.3	6.8
144 × 192 × 160	173	6.8	4.8	5.4
160 × 160 × 160	149	6.6	5.0	5.2