光子学报, 2013, 42 (12): 1528, 网络出版: 2013-12-16
X射线成像闪烁体的光场渲染
Light Field Rendering of Scintillator for XRay Imaging
相机阵列 X射线闪烁体 数字重聚焦 光场成像 Camera array Scintillator for Xray imaging 3ds Max 3ds Max Digital refocus Light field Photography
摘要
提出了一种将数字光场成像技术应用到X射线闪烁体成像系统的方法.分析了闪烁体的发光原理和光强分布,设计了基于相机阵列的X射线光场成像系统,并用计算机模拟了闪烁体发光模型并进行了仿真.在3ds Max中采用相机阵列捕捉闪烁体发出的光线,获取不同视角的图像,合成了模拟微透镜阵列成像的光场数据,通过数字重聚焦方法得到闪烁体不同发光平面的图像序列.实验结果表明:未采用光场成像技术的X射线光学成像系统,景深较小,只能使闪烁体的一部分聚焦,其余部分会降低图像分辨率;而利用光场成像技术,在不改变光学系统基本结构的基础上,扩大了光学系统的景深,使整个闪烁体都在聚焦范围内,可以减小对闪烁体厚度的要求,获得比较好的图像质量,为实际模型的建立提供理论依据.
Abstract
A new method that combining digital light field photography technology with the XRay scintillator imaging system is proposed. The scintillation luminescence principle and light intensity distribution are analyzed, a XRay light field imaging system is designed based on camera arrays, and the scintillation luminescence model is simulated. Camera arrays in 3ds Max is used to capture the light from scintillator and get the images from different viewpoints. The light field data is generated that is similar to the data from microlens based system and get the images of arbitrary planes in the scintillator using the digital refocus algorithm. The simulation experiments show that XRay imaging system without using light field photography has a small depth of field; only a part of the scintillators are focused by optics and the defocused rest will decrease the image resolution; on the contrary, system with light field photography can extend the depth of field of the optical system to reduce the requirement of the scintillator thickness without changing the basic structure of the optical system; it can also get the image of the same resolution. The simulation provides theoretical basis for the establishment of real model.
王小龙, 罗守华, 李光, 杨晶. X射线成像闪烁体的光场渲染[J]. 光子学报, 2013, 42(12): 1528. WANG Xiaolong, LUO Shouhua, LI Guang, YANG Jing. Light Field Rendering of Scintillator for XRay Imaging[J]. ACTA PHOTONICA SINICA, 2013, 42(12): 1528.