基于波前再现的三维显示信息量及其时空带宽积的研究

Wavefront reconstruction technique, represented by holography, can achieve the most vivid and the most nature three-dimensional images, which will be the most promising technique in future three-dimensional display. Computer-generated holography has attracted special attention in three-dimensional display for its flexible wavefront reconstruction ability. In computer-generated holography, any real or virtual scene can be encoded into holograms and the digitized holograms can be transmitted by internet and displayed by electronic devices, which provides the technique basis for real-time display. However, at present its application in real-time dynamic three-dimensional display has been impeded by huge space-time bandwidth product due to mass information contained in holograms. In this project the work will be carried out to solve the issue and bring about real-time three-dimensional display. First, by analyzing the essence of wavefront carrying the three-dimensional information of object, the expression of amount of information in three-dimensional display based on wavefront reconstruction, as well as the extreme limit of amount of information for human three-dimensional vision, will be explored. Then, the research of the theory and techniques will be carried out on how to simplify the amount of information in computer-generated holograms in which the wavefront carrying the three dimensional information of object is encoded. Based on the simplified information content, new encoding methods and fast algorithms for computer-generated holograms will be proposed. Last, the relationship between both space bandwidth products of the wavefront encoded in holograms and display device will be analyzed. According to the invariance principle of degrees of freedom, the potential of three-dimensional display based on wavefront reconstruction by using the existing high resolution display devices will be investigated. In conclusion, the target of the project is that, based on the establishment of a more perfect wavefront reconstruction three-dimensional display theory, the methods and techniques of information simplification, fast encoding and the improvement of space bandwidth product of display device will be proposed for computer-generated holographic display.

基于光的波前重建技术是未来三维显示的发展方向，以全息术为代表的波前重构可以实现最逼真、最自然的三维显示。在全息术类型中，计算全息更加灵活，可以实现任意现实和虚拟场景的波前编码，而且因其全息图的数字化，为全息图的传输和实时显示提供了技术基础。但全息图海量信息量又将导致巨大的时空带宽积，制约了它在实时动态三维显示中的应用。本课题针对这一问题，通过分析光的波前携带三维物体信息的本质，研究基于波前重构三维显示的信息量表达，分析人类三维视觉所需信息量极限；以计算全息图作为三维信息编码载体，研究全息信息量的简化理论、技术和新的全息图编码方法和实时快速算法；分析光的波前和显示器件时空带宽积的关系，并根据自由度不变原理，探讨利用现有的高分辨显示器件进行波前重构三维显示的可能性。本课题研究目标是：在建立较为完善的三维显示信息理论基础上，提出计算全息信息简化、快速编码以及提高显示器件空间带宽积的方法与技术。

基于光的波前重建技术是未来三维显示的发展方向，以全息术为代表的波前重构可以实现最逼真、最自然的三维显示。在全息术类型中，计算全息更加灵活，可以实现任意现实和虚拟场景的波前编码，而且因其全息图的数字化，为全息图的传输和实时显示提供了技术基础。但全息图海量信息量又将导致巨大的时空带宽积，制约了它在实时动态三维显示中的应用。研究三维显示信息量的问题，对于实现真正的实时动态三维显示具有重要的学术和应用价值。.根据本项目的研究计划，研究了全息三维显示的信息量与再现像的视差角与视场角的关系，指出全息三维显示的巨大信息量是为了提供足够的视差和视场，以达到人眼立体视觉效果。在牺牲垂直视差并保证足够的水平视差角和视场角的条件下，利用光栅对全息图进行取样，计算了光栅取样全息图对信息压缩的极限，分析了简化后全息图再现像的特点和存在的问题，对于信息压缩后的光栅取样全息图的再现进行了设计。在对三维显示信息量的研究中，从部分相干理论出发，提出利用互强度这一概念来阐述和度量光波场上任意两点光扰动的关联程度，并提出利用回转椭球波函数集表示三维成像像面互强度分布，从而得出在部分相干光照明下成像光场的自由度数。对于三维显示的彩色信息的研究的相关实验，基于信息简化理论，形成了全息三维显示原理样机。举办了“国际三维图像获取与显示技术：感知与应用研讨会（Conference on Three Dimensional Image Acquisition and Display Technology， DIADT 2016)”国际会议。.项目资助发表核心论文8篇，待发表两篇 ，总结波前再现三维显示信息量研究成果，形成专著《波前再现三维显示》，由科学出版社出版。培养硕士生5名，博士研究生1名，其中3名已经取得硕士学位。项目投入经费80万元，支出50.21328万元，结余297867.17。剩余经费将用于研制基于时空复用的彩色全息动态三维显示系统。