The light-field display (LfD) radiance image is a raster description of a light-field where every pixel in the image represents a unique ray within a 3D volume. The LfD radiance image can be projected through an array of micro-lenses to project a perspective-correct 3D aerial image visible for all viewers within the LfDs projection frustum. The synthetic LfD radiance image is comparable to the radiance image as captured by a plenoptic/light-field camera but is rendered from a 3D model or scene. Synthetic radiance image rasterization is an example of extreme multi-view rendering as the 3D scene must be rendered from many (1,000s to millions) viewpoints into small viewports per update of the light-field display. However, GPUs and their accompanying APIs (OpenGL, DirectX, Vulkan) generally expect to render a 3D scene from one viewpoint to a single large viewport/framebuffer. Therefore, LfD radiance image rendering is extremely time consuming and compute intensive. This paper reviews the novel, full-parallax, BowTie Radiance Image Rasterization algorithm which can be embedded within an LfD to accelerate light-field radiance image rendering for real-time update.
With the provision of motion parallax and viewing convenience, multi-view autostereoscopic displays have been popular in recent years. Obviously, increasing the number of views improves the quality of 3D images/videos and produces to better motion parallax. The tradeoff is the larger number of view images required to generate in real time leading to the need of the huge amount of computing resources for the systems. In fact, people often focuses on the distinctive objects in a scene. For achieving the same level of motion parallax, it can use more views to present distinctive objects and less views for the rest. As a result, fewer computing resources are required for rendering multi-view images. With exploiting this principle, a new multi-view rendering scheme based on visual saliency is proposed for the application of autostereoscopic displays. The new method uses saliency maps to extract distinctive regions with different saliency level in a scene and dynamically control the number of views to generate for them. Points in the distinctive regions with high saliency use more views, while points in the regions with low saliency use less views. By controlling the number of views in use for different salient regions, the proposed scheme can maintain low computation complexity without causing significant degradation in 3D experience. In this paper, a 2D+Z format based multi-view rendering system with the use of saliency maps is presented to illustrate the feasibility of the new scheme. Subjective assessment results demonstrate that the saliency map based multi-view system has slight degradation in 3D performance compared with true 28-view system and achieves 55% reduction in computation complexity.