Abstract

Spatially multiplexed holographic stereographic images suffer severe 3-D distortions as the image approaches the stereogram surface if conventional photographically recorded perspective views are used in their creation. Because highly astigmatic optics are most often used in the holographic recording of such stereograms, correspondingly astigmatic optics ought to be used during the recording of the perspective views if distortion is to be avoided. Unfortunately, the cylindrical optics required are generally unwieldy and heavily aberrated. However, if completely synthetic images are to be rendered from a digital data base, conventional ray-tracing algorithms can be modified to simulate the effects of idealized cylindrical lenses of any proportions. In practice, rather than literally modeling cylindrical refracting surfaces, the rays for each view are cast through crossed vertical and horizontal slits that are located in the object and at the viewing location, respectively. The resulting astigmatically predistorted perspective views have singularities at the distance corresponding to the intended stereogram surface, but the composite synthesized holographic stereographic image is found to be undistorted on reconstruction, even though it extends up to and through the stereogram surface.

© 1986 Optical Society of America