Media Production for Computer-Generated Holography.

Abstract

Computer Generated Holography (CGH) is an immersive next-generation display technology with significant potential. It is the only technique that allows the reconstruction of true three-dimensional imagery while not compromising display resolution - achieved through the diffraction and interference of light. When a hologram is illuminated with coherent light and the replay field is observed, all psychological and physiological depth cues of the image are preserved and the scene is interpreted as reality by the viewer. CGH has recently received significant attention from researchers, with applications in Virtual/Augmented Reality, Head-Up Display, and larger panels. Providing natural depth perception (defocus, parallax, occlusion), high dyanamic ranges and wide colour gamuts. In CGH research there is a focus on algorithmic and hardware developments, but a failure to make use of advancements in image rendering made in Computer Graphics. Works largely implement their own basic renderers, or use only RGB + Depth information rendered from a single perspective. Neither of these can yet replicate the full effects of a realistic 3D scene with complex material properties, and do not match the feature set and quality of a 2D final-frame rendering and compositing process. In collaboration with partner company VividQ, this work develops the relationship be- tween renderer and display with a practical framework of methods that support industry practice. By utilising existing production renderers, extensive features and familiar working environments are enabled for both high quality 2D and 3D content delivery. This work intro- duces methods such as "holographic compositing", which composites imagery in frequency space to enable the viewing of multiple depth and view inputs with improved occlusions - enabling support for transparencies, motion-blur, refractions, reflections, volumetrics such as smoke, fire and fog, fine details such as fur and improved accuracy in edge details. A unique multi-view “discrete-hybrid” hologram generation algorithm is also introduced, with appropriate production tools, allowing an observer to experience view-dependent effects such as large parallax shifts and changes in perspective. The developments presented in this work are primarily proved via computer simulations. Though, many of the methods described have already been implemented and proven in the partner company’s software product.