Several methods of increasing the speed and simplicity of the computation of off-axis transmission holograms are presented, with applications to the real-time display of holographic images. A bipolar intensity approach enables a linear summation of interference fringes, a factor of two speed increase, and the elimination of image noise caused by object self- interference. An order of magnitude speed increase is obtained through the use of precomputed look-up tables containing a large array of elemental interference patterns corresponding to point source contributions from each of the possible locations in image space. Results achieved using a data-parallel supercomputer to compute horizontal-parallax- only holographic patterns containing 6 megasamples indicate that an image comprised of 10,000 points with arbitrary brightness (grayscale) can be computed in under one second.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.