非均匀混浊介质多光谱反射成像的仿真与实验研究  

Simulation and experimental studies of heterogeneous turbid medium by multispectral reflectance imaging

作　　者：杨博赞 杨春梅[1] 撒昱[1] 丁俊华[2] 李梅花[3] 梁晓会[3] 冯远明[1] 胡新华[4] 

机构地区：[1]天津大学生物医学工程系,天津300072 [2]东卡罗莱纳大学计算机科学系,北卡罗莱纳州格林维尔27858 [3]军事医学科学院实验仪器厂,北京100850 [4]东卡罗莱纳大学物理系,北卡罗莱纳州格林维尔27858

出　　处：《光电子．激光》2014年第12期2437-2446,共10页Journal of Optoelectronics·Laser

基　　金：国家自然科学基金(81171342;81201148)资助项目

摘　　要：提出了一种采集高动态范围多光谱反射率的实验方法,并通过测量5个非均匀混浊介质样品在全视场照射条件下和500-940nm波长范围内的反射图像数据证明了本方法的可行性。同时采用在辐射传输理论框架下建立的并行iMC蒙特卡罗仿真模型,通过使用漫反射标准板准确记录入射光束能量分布,输入至iMC仿真程序,获得可与反射率测量数据相比较的反射率仿真图像数据。本文工作为求解根据反射率确定非均匀混浊介质样品的光学特征与几何参数的逆问题提供了实验与理论工具。Development of quantitative and non-invasive methods for determination of optical parameters of turbid media can have wide applications in material analysis and medicine. We present a novel method to acquire multispectral and high dynamic range reflectance images that can be compared with simulated image data to investigate the dependence of the image contrast on the optical properties of heterogeneous turbid samples. At each wavelength, the distribution of reflected light intensity at the surface of a turbid phantom is acquired from a camera with 4 different exposure times which are used to determine a high dynamic range reflection image. The incident beam profile is measured with a diffuse reflectance standard to obtain a reflectance image at each wavelength. The image of the incident beam profile is also imported into a Monte Carlo model to accurately obtain the simulated reflectance images within the framework of radiative transfer theory. We have measured reflectance images of 5 heterogeneous turbid samples in the spectral range from 500 nm to 940 nm. By accurate measurement of reflectance image with a full-field illumination using a diffuse reflectance standard and image simulation with the Monte Carlo method, we demonstrate the feasibility to obtain the optical parameters of the turbid samples with the measurement and simulation methods in a wide spectral region from 500 nm and 940 urn.

关 键 词：混浊介质 光散射 反射成像 

分 类 号：O433.4[机械工程—光学工程]