Ultragram: a generalized holographic stereogram

A method for producing holographic stereograms with reduced geometrical constraints is presented. The type of holographic stereogram produced, called the ULTRAGRAM, can offer a combination of large viewing zone, arbitrary viewing distance, minimal image distortion, and high spatial resolution, depending on alterable parameters in the image processing software. Computer-based image processing techniques are used to mimic the effect of optical devices while permitting simple re-configurability. The ULTRAGRAM holographic exposure apparatus can be built with reduced attention to the final viewing geometry. An astigmatic computer graphics camera design greatly simplifies image generation. The techniques described are applicable to both one and multi-step stereograms, optical predistortion methods, and both horizontal and full-parallax systems.