Principle And Establishment Of Multi-projector-type Light Field Display

As the three-dimensional(3D) technology attracts much more attention today, various real-ization of 3D technologies are developing rapidly. Light field display technology is one of them that with the principle of reconstructing the light field distributions of the objects in space. With the advantage of getting rid of head-mounted devices, reconstructing of perspective relation and occlusion and providing of smooth motion parallax, light field display has been widely focused. This paper starts from the description of plenoptic function and describes the four-dimensional light field description in free space, leading to the basic mapping relation of the light field display. According to the relation, light field mapping algorithm of the surrounded-type multi-projection light field display is deduced. It builds the theoretical foundation of constructing a surrounded-type multi-projection light field display system.Based on the light field mapping theory, we construct a large-scale 360° surrounded-type multi-projection light field display system. Characteristics and construction schemes of the projector array and the diffuser are described. Considering the great amount of information of a 3D display, the schemes of data segmentation and synchronized output with the computer cluster and the screen splitters are determined, cooperating with the hardware system, the procedure of dynamic light field mapping and rendering are described, together with the data segmentation and synchronized output process. The calibration both with hardware and software is also proposed. The large-scale 360■ surrounded-type multi-projection light field display system provides a platform for experiments of light field technologies and for analyses and improvements of the display performance.Analyses and improvements of the display performance is the mainly research area of the light field display based on the theories. A software simulation of the light field display systems are proposed to adjust and compare the performance of the systems conveniently. Based on the light field display platform, a comparison between the multi-view mapping algorithm and the light field mapping algorithm with similar hardware configuration is implemented. The validation of the comparison is implemented on the platform and shows the strength of the light field mapping algorithm. The problem of suffering image distortions due to the approximation in the light field mapping algorithm is figured out in this paper. A software optimization is proposed aiming to reduce the distortion of the scenes that is far from the screen. The experiments show the improvement of display performance after the optimization.Explorations for improving the experience of watching 3D displays are also implemented. The main idea is reconstructing the public display area outside the device in order to provide the convenience of touching the 3D scenes directly. To the small-scale display system constructed with LCD and lens array, fusion of the real objects and the reconstructed scenes are realized. Audiences can also "touch" the scene directly. To the large-scale display system with projector array, the audiences can enter the public display area inside the arc of the concave screen. The audiences can see all the projectors surrounding around. Thus the system provides the experience of immersive 3D scenes, which enhances the presence sensation.Finally, conclusions of the the paper are made. The potential improvements are discussed and shows a direction of future research on light field display technologies.