Ray‐based and Wavefront‐based 3D Representations for Holographic Displays

Abstract

A three-dimensional (3D) holography display is capable of reproducing extremely high-quality 3D images by wavefront reconstruction, and its advantage against ray-based 3D display is the capability to reproduce deep 3D scenes at high resolution. One of the important issue in holographic display is the calculation of holograms from 3D data, because it requires wavefront-based rendering that is much more complicated than conventional ray-based computer graphics. Although ray-based rendering techniques have been applied to hologram computation, they cause reduction of resolution as in the case of ray-based displays. This chapter addresses a technology that converts 3D data represented by light-rays into wavefront data and vice versa at ray-sampling (RS) planes defined near the objects to be displayed, and a new method is proposed for the computation of hologram using a RS plane. The proposed method enables to employ the advanced rendering techniques for occlusion processing, surface shading, specular or glossy surfaces, and translucent objects in the computation of holograms, without loss of the advantage of holographic displays. A scanning vertical camera array system is presented for capturing high-density light-field information, which are applied to computational holography and holographic prints. Experimental results demonstrate that the proposed ray-wavefront conversion technique allows the realistic display of deep 3D images at high resolution.