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来显示真实感图像的技术，并取得了以下结果：(A)开发了三维光线信息获取系统为了获取不损失光泽和各向同性反射的全视差三维光线信息，开发了一种全视差三维图像扫描系统。该系统对垂直面阵的CCD摄像机进行水平扫描，并利用基于图像的绘制技术对垂直视差信息进行内插。通过实验获得了光线信息，获得了逼真的三维图像。(B)三维图像硬拷贝再现真实感。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，即基本全息图的尺寸为50um或100um，并且由于基本全息图而产生的点结构几乎看不见。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几乎等于衍射极限的角分辨率。在此基础上，记录了一个由800×668个100um尺寸的元素全息图组成的全息图，每个元素再现100×100光线，结果表明，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角度相关反射的有效性，并揭示了对未来高真实感显示技术的要求。

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.