基于视场拼接的全视差三维显示系统

提出了一种新的基于视场拼接的全视差三维显示方法及图像生成方案.系统核心部分由一个微投影机阵列、一个反射光路和一个散射屏组构成,图像生成方案采用基于OpenGL的算法实现.为了验证所提出的基于视场拼接理论的正确性,利用液晶显示器、菲涅耳镜组、定向散射屏和背投式反射光路搭建了实验样机.该装置可以在更紧凑的系统结构下显示包括横向视差和纵向视差在内的三维图像,并且通过图像生成算法的配合实现了动态三维显示效果.     

基于视场拼接的全视差三维显示系统

提出了一种新的基于视场拼接的全视差三维显示方法及图像生成方案.系统核心部分由一个微投影机阵列、一个反射光路和一个散射屏组构成,图像生成方案采用基于OpenGL的算法实现.为了验证所提出的基于视场拼接理论的正确性,利用液晶显示器、菲涅耳镜组、定向散射屏和背投式反射光路搭建了实验样机.该装置可以在更紧凑的系统结构下显示包括横向视差和纵向视差在内的三维图像,并且通过图像生成算法的配合实现了动态三维显示效果.     

Depth-enhanced integral imaging system with convex and composite concave micro-lens arrays

A depth-enhanced integral imaging system is proposed by using a convex micro-lens array and a composite concave micro-lens array. The convex-micro-lens array is used to provide a virtual elemental image array for the composite concave micro-lens array. The composite concave micro-lens array which has two focal lengths is used to display integral images with the virtual elemental image array. Compared with the conventional integral imaging, the proposed system can form the 3D image around two image planes with viewing angle being enhanced remarkably. The principle of the enhancement of the image depth is explained in detail and the experimental results are presented.     

360 degree realistic 3D image display and image processing from real objects

A 360-degree realistic 3D image display system based on direct light scanning method, so-called Holo-Table has been introduced in this paper. High-density directional continuous 3D motion images can be displayed easily with only one spatial light modulator. Using the holographic screen as the beam deflector, 360-degree full horizontal viewing angle was achieved. As an accompany part of the system, CMOS camera based image acquisition platform was built to feed the display engine, which can take a full 360-degree continuous imaging of the sample at the center. Customized image processing techniques such as scaling, rotation, format transformation were also developed and embedded into the system control software platform. In the end several samples were imaged to demonstrate the capability of our system.     

基于自由曲面的裸眼3D显示柱透镜光栅设计

设计了一种用于裸眼3D显示屏的低串扰新型双面柱透镜光栅板,光栅板的入射面为等间距排列的与显示器子像素数量相同的凹形自由曲面光栅结构,出射面为斜置的凸形自由曲面光栅结构.根据裸眼3D显示原理和几何光学原理推导了双面光栅板的光栅单元自由曲面设计公式和光栅参数计算公式.通过MATLAB编程计算和SolidWorks软件建模得到光栅板模型.用TracePro软件对所设计的光栅板模型进行光线追迹仿真,结果表明:参数优化后的6视点斜置柱透镜双面光栅3D显示在最佳视角的图像串扰度为0.068%,与传统6视点斜置柱透镜光栅的最佳视角图像串扰度相比降低了2个数量级,并且在观看距离2 000mm~3 000mm范围内图像串扰度基本不变.     

Multi-projector-type immersive light field display

A light field three-dimensional （3D） display with multi-projectors and a concave screen is proposed. The system sets the viewing area at the center of the concave screen, making viewers enter the center of the system to watch 3D scene around them. The surrounded 3D scene provides viewers a feast of enhanced immersive experience. The light field principle, rendering algorithm, selection of viewing area and experi- mental results are discussed in the letter, showing the potential of being an all-around-type immersive 3D display by employing more projectors.     

One-dimensional integral imaging based on parallax barrier

One-dimensional integral imaging (1DII) which only has horizontal disparity is a practical solution of high resolution in the vertical direction, low-cost, easy-viewable three-dimensional (3D) display. A 1DII based on a parallax barrier is proposed in this paper. The 1DII consists of a parallax barrier and a display panel. The operation principle and parameter calculation of the 1DII are described in detail. Two prototypes of the proposed 1DII and conventional 1DII based on a lenticular lens array are developed. The proposed 1DII improves the quality of the 3D image and provides larger viewing angle than that based on a lenticular lens array, and it is simpler and has lower cost than that based on a lenticular lens array.     

Crosstalk elimination in multi-view autostereoscopic display based on polarized lenticular lens array

An autostereoscopic display composed of a directional backlight,an image display panel,a striped half-wave plate,and a polarized lenticular lens array is proposed.The directional backlight emitting the parallel light can redirect the cones of light to lenticular lens array and reduce the chromatic spatial-interference effect.The striped half-wave plate,located in front of the image display panel,transformed the polarization direction of the lights from the directional backlight into two mutually perpendicular directions.The polarized lenticular lens array not only can divide the light from the left and right view images to send to left and right eyes but also can reduce the crosstalk of the stereoscopic images.The proposed autostereoscopic display can produce high quality stereoscopic images without crosstalk at the optimal viewing distance.     

空间光调制器曲面拼接实现全息三维显示视角拓展

本文对多空间光调制器不同拼接方式拓展全息三维再现像视角的方法进行了分析,基于多片空间光调制器拼接拓展视角的思想,利用平面反射镜、分光镜和两片透射式空间光调制器设计了曲面拼接系统,进行了全息三维再现像的视角拓展实验研究。用该系统对四棱锥物体的层析菲涅尔衍射全息图进行再现,结果表明,总视角由基于单片空间光调制器的1.7°增大到3.2°,即拓展到约1.9倍,分光镜能够消除两片空间光调制器间的间隙,实现无缝拼接。该方法同样适用于更多空间光调制器的曲面拼接中,可以有效地拓展全息再现像的视场角大小。     

基于固定校正板和透镜阵列的机载共形窗口像差校正

为了校正大扫描视场机载共形窗口引入的像差,提出一种基于固定校正板和透镜阵列的静态校正方法。首先使用固定校正板校正静态像差;然后在像面前安置固定的透镜阵列,利用透镜阵列中的各个透镜单元分别校正不同扫描角度的动态像差;最后基于所提方法设计应用在机载共形光学系统中的像差校正器。设计结果表明,所提方法在±42°的扫描视场范围内能够良好地校正共形窗口引入的像差。与其他动态或静态校正方法相比,所提方法可以实现大扫描视场机载共形光学系统像差的校正,同时降低机载共形光学系统的质量,提高系统的稳定性。     

Full-parallax three-dimensional display using new directional diffuser

A full-parallax three-dimensional(3D) display using a new directional diffuser is demonstrated.The display could present 3D images with 45 views comprising 9 horizontal views by 5 vertical views.The resolution and size of the 3D images displayed are 226×226 pixels and 300×300(mm).The new directional diffuser consisting of two perpendicular lenticular sheets can be widely used in the display domain owing to its low cost and simple process.     

Wide-viewing projection-type integral imaging system with an embossed screen

A projection-type integral imaging system with an embossed screen is proposed to realize a wide viewing angle for the reconstructed image. The embossed screen is designed for virtual integral imaging in a projection-type system. It can enhance the viewing angle by increasing the effective region for each elemental image. The experimental result that verifies the merit of the proposed method is presented.     

宽覆盖高分辨率机载相机光学系统设计

针对机载相机广域高效航拍作业需求,采用新型级联光学成像结构,设计了一种宽覆盖高分辨率机载相机光学系统。该系统由对称前置同心物镜和中继转像透镜阵列组成,对称前置同心物镜获取剩余像差均匀的宽视场曲面像,中继转像透镜阵列对该曲面像进行视场细分、剩余像差校正及中继成像。所设计的机载相机光学系统焦距为60 mm、F数为3.4、视场角可达132°。基于一阶理论和像差特性,在不同飞行高度对地观测时,研究了机载相机光学系统的成像质量与宽视场曲面像的关系,获得系统在不同飞行高度实现清晰成像的方法。通过像质评价,结果表明,优化设计的系统在低空、中空及高空进行对地观测时,像面光线追迹点列图方均根半径均优于1.6μm,在奈奎斯特频率为230 lp/mm处,调制传递函数均达0.4,系统成像性能优异且像质均匀。新型级联光学成像系统适用于不同飞行高度的机载相机。     

消除自由立体显示串扰的定向背光源设计

定向背光柱透镜光栅式多视点自由立体显示器的串扰和亮度均匀性问题是影响其广泛应用的主要因素之一.本文通过分析串扰产生的原因,根据偏轴光线的成像光学原理,推导出液晶显示屏光开关板列单元与柱透镜组成的偏轴光学系统的参数计算式.提出一种液晶显示屏光开关蝶形单元结构,设计了采用该蝶形单元的定向背光自由立体显示背光源模组.模拟仿真结果表明:所设计的定向背光自由立体显示背光源可消除自由立体显示的串扰;在视点平面90%观看区域的串扰度小于0.5%,光束10%峰值宽度的串扰面积比γ=0,光束90%峰值宽度比普通液晶单元结构的增大37%,改善了不同位置观看图像亮度变化大的问题.     

All-around holographic three-dimensional light field display

Technology for all-around holographic three-dimensional (3D) light field display is proposed in this paper. A plane mirror keeps rotating around the optical axis. At each angular position, the mirror-image's Fourier CGH of the target object is projected onto the mirror. The reflected CGH contributes a specific viewing angle range to the target object. Linking up all viewing angle ranges in the horizontal plane, all-around display can be realized via the “afterimage” effect. An all-around holographic 3D light field display is implemented experimentally here with a 60 Hz SLM by introducing an observer tracking unit in the proposed display system.     

采用色差先验约束的像差校正技术

本文通过分析自然图像的边缘3个通道之间的关联性,提出"同一物体的边缘在3个颜色通道应处于相同位置"的色差先验约束,该约束在数学上近似为各通道的相对导数相等,基于此色差先验约束,建立了一种新的像差校正模型即图像解卷积模型,并给出了基于交替方向乘子法的模型求解算法。实验结果表明:本文的像差校正技术可以提升图像的峰值信噪比10 dB以上,明显优于目前主流的BM3D和YUV算法,并且视觉提升效果明显,基本满足普通光学系统对像差的校正要求。     

基于人眼视觉的集成成像三维显示分辨率的比较

为了对不同集成成像系统三维显示应用中的视觉分辨效果进行表征, 提出了一种基于人眼视觉的集成成像三维显示分辨率的分析比较方法. 通过分析集成成像三维显示系统的分辨率与人眼在最佳显示观看距离下分辨本领的关系, 定义了相对分辨率参数, 分析了其与集成成像三维显示实际观看时视觉分辨效果的关系. 研究结果表明, 透镜阵列的大小对集成成像三维显示的视觉分辨效果有重要的影响. 针对两个系统实例的理论计算结果表明, 系统间的相对分辨率参数差异是传统分辨率差异的1.75倍, 实验结果与理论分析一致. 该研究方法对三维显示分辨率的评价有一定的指导意义.     

Three-dimensional display with a long viewing distance by use of integral photography

We developed a technique of three-dimensional (3-D) display for distant viewing of a 3-D image without the need for special glasses. The photobased integral photography (IP) method allows precise 3-D images to be displayed at long viewing distances without any influence from deviated or distorted lenses in a lens array. We calculate elemental images from a referential viewing area for each lens and project the corresponding result images to photographic film through each lens. We succeed in creating an image display that appears to have three dimensionality even when viewed from a distance, with an image depth of 5.7 m or more in front of the display and 3.5 m or more behind the display. To the best of our knowledge, the long-distance IP display presented here is technically unique because it is the first report of generation of an image with such a long viewing distance.     

集成成像三维显示系统显示性能的研究进展

集成成像三维显示技术是利用透镜阵列获取和显示立体图像的一种三维显示技术。本文首先综述了集成成像三维显示系统的特点,考虑其系统性能主要受分辨率、景深和观看视场角的限制,对近年来集成成像三维显示系统在增大分辨率、景深和观看视场角方面的研究进展做了综合论述,比较分析了各种改进方法的优劣。最后,对我国集成成像三维显示技术的研究现状进行了总结,并简述了本研究小组在该领域取得的若干研究成果。     

Autostereoscopic 3D projection display based on two lenticular sheets

We propose an autostereoscopic three-dimensional (3D) projection display. The display consists of four projectors, a projection screen, and two lenticular sheets. The operation principle and calculation equations are described in detail and the parallax images are corrected by means of homography. A 50-inch autostereoscopic 3D projection display prototype is developed. The normalized luminance distributions of viewing zones from the simulation and the measurement are given. Results agree well with the designed values. The proposed prototype presents full-resolution 3D images similar to the conventional prototype based on two parallax barriers. Moreover, the proposed prototype shows considerably higher brightness and efficiency of light utilization.