3D image reproduction of angular dependent reflection of object surface by using holographic stereogram

本项目的目的是开发利用全息立体图技术再现物体表面的光泽和各向异性反射的逼真图像显示技术，并取得了以下成果：（A）用于捕获3D光线信息的系统的开发为了捕获全视差3D光线信息而不损失光泽和各向异性反射，开发了一种全视差三维图像扫描系统。在该系统中，一个垂直的CCD相机阵列水平扫描，并使用基于图像的渲染技术插值的垂直视差信息。实验中利用该系统捕获了光线信息，获得了真实感较强的三维图像。(B)全视差全息立体图的光学记录系统的精度得到提高，使得高密度记录成为可能，即，基本全息图尺寸为50 μ m或100 μ m，并且由于基本全息图而产生的点结构几乎不可见。此外，还测量了再现光的角分辨率，证实了全视差全息立体图可以实现与衍射极限相当的角分辨率。在此基础上，记录了由800×668张100 μ m的基元全息图组成的全息图，每个基元再现100×100条光线，表明该技术可以再现高质量的真实感图像.在此基础上，讨论了该技术再现物体表面随角度变化的反射的有效性，揭示了未来高真实度显示技术的要求。

The aim of this project is to develop technologies for realistic image display by reproducing the gloss and unisotropic reflections of object surface using the technology of holographic stereogram, and following results are obtained ;(A) Development of the system for capturing 3D light-ray informationIn order to capture full-parallax 3D light-ray information without loss of gloss and unisotropic reflections, a full-parallax 3D image scanning system is developed. In the system, a vertical array of CCD cameras is scanned horizontally, and the vertical parallax information is interpolated using image-based rendering technique. The light-ray information is captured by the system experimentally, and realistic 3D image is obtained.(B) The reproducibility of reality by 3D image hardcopyThe accuracy of the optical recording system of full-parallax holographic stereogram is improved, so that high-density recording becomes possible, i.e., elementary hologram size is 50um or 100um, and the dot structure due to the elementary hologram is almost invisible. In addition, the angular resolution of the reconstructed light-rays is measured, and it is confirmed that the full-parallax holographic stereogram can realize the angular resolution almost equivalent to the diffraction limit. Based on those results, a hologram consisting of 800×668 elementary holograms of 100um size, each of elements reproduce 100×100 light-rays, is recorded, and it is shown that high-quality realistic image reproduction is possible by the proposed technique.Based on the above results, discussions are made on the effectiveness of the technology for reproducing the angular-dependent reflection of object surfaces, and the requirements for the future high-reality display technology are also revealed.