2D and 3D optimal parallel image warping

Spatial image warping is useful for image processing and graphics. The authors present optimal concurrent-read-exclusive-write (CREW) and exclusive-read-exclusive-write (EREW) parallel-random-access-machine (PRAM) algorithms that achieve O(1) asymptotic run time. The significant result is the creative processor assignment that results in an EREW PRAM forward direct warp algorithm. The forward algorithm calculates any nonscaling affine transform. The EREW algorithm is the most efficient in practice, and 16k processor MasPar MP-1 can rotate a 4 million element image in under a second and a 2 million element volume in 1/2 of a second. This high performance allows interactive viewing of volumes from arbitrary viewpoints and illustrates linear speedup