Rendering interactive holographic images

We present a method for computing holographic patterns for the generation of three-dimensional (3-D) holographic images at interactive speeds. We used this method to render holograms on a conventional computer graphics workstation. The framebuffer system supplied signals directly to a real-time holographic (“holovideo”) display. We developed an efficient algorithm for computing an image-plane stereogram, a type of hologram that allowed for several computational simplifications. The rendering algorithm generated the holographic pattern by compositing a sequence of view images that were rendered using a recentering shear-camera geometry. Computational efficiencies of our rendering method allowed the workstation to calculate a 6-megabyte holographic pattern in under 2 seconds, over 100 times faster than traditional computing methods. Data-transfer time was negligible. Holovideo displays are ideal for numerous 3-D visualization applications, and promise to provide 3-D images with extreme realism. Although the focus of this work was on fast computation for holovideo, the computed holograms can be displayed using other holographic media. We present our method for generating holographic patterns, preceded by a background section containing an introduction to optical and computational holography and holographic displays.