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

本项目旨在利用全息立体图技术再现物体表面的光泽度和各向同性反射，开发逼真的图像显示技术，并获得以下结果；(A)三维光线信息捕获系统的研制为了捕获全视差三维光线信息，同时不损失光泽度和反射各向同性，研制了全视差三维图像扫描系统。在该系统中，CCD相机垂直阵列被水平扫描，垂直视差信息采用基于图像的绘制技术插值。该系统通过实验采集光线信息，得到了真实的三维图像。提高了全视差全息立体图光学记录系统的精度，使高密度记录成为可能，即初等全息图尺寸为50um或100um，由于初等全息图而产生的点结构几乎不可见。此外，还测量了重建光线的角分辨率，证实了全视差全息立体图可以实现几乎相当于衍射极限的角分辨率。基于这些结果，记录了一个由800×668大小为100um的基本全息图组成的全息图，每个元素再现100×100光线，并表明通过所提出的技术可以实现高质量的逼真图像再现。基于上述结果，讨论了该技术在再现物体表面角相关反射方面的有效性，并揭示了未来高现实显示技术的要求。

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.