基于遗传算法的光学层析成像的结构优化  

Configuration Optimization of Optical Tomography Based on Genetic Algorithm

作　　者：郑晓钊 姚纪阳 李华军 余善恩[1] Zheng Xiaozhao;Yao Jiyang;Li Huajun;Yu Shanen(School of Automation,Hangzhou Dianzi University,Hangzhou 310018,Zhejiang,China)

机构地区：[1]杭州电子科技大学自动化学院,浙江杭州310018

出　　处：《光学学报》2023年第3期49-59,共11页Acta Optica Sinica

基　　金：国家自然科学基金(51906053)。

摘　　要：光学层析成像传感器结构由发光元件与感光元件组成,对重建图像的精度有重要作用。鉴于此,对扇形发光与感光元件的分布进行了优化研究。首先,将发光与感光元件的位置信息构建为角度向量。然后,引入灵敏场均匀性参数作为该结构的评价指标,并通过仿真实验验证了该指标的可靠性。最后,基于遗传算法对传感器结构进行优化,将角度向量作为优化对象来确定传感器结构,并将灵敏场均匀性参数作为适应度函数。在所获得的优化结构中,发光与感光单元分布不均匀,均匀性参数为0.288。多种具体分布的图像重建实验表明,该传感器优化结构在重建精度、图像准确性和噪声等方面均优于传统分布和随机分布。Objective Optical tomography aims to reconstruct the crosssectional distribution from numerous projections along various orientations.Due to its'hardfield',high spatial and temporal resolution,this technique has been widely used in multiphase flow monitoring,temperature and species concentration measurement and functional tissue imaging.Optical tomography adopts light emitters to emit laser beams,which are attenuated by the medium.The outgoing light is then detected by photosensitive receivers.Reconstruction algorithms are used to reconstruct the absorption distribution of the medium.Intrusively,increasing light beams and receivers will improve the reconstruction performance.However,this approach is not appropriate when the light access or installation space is limited.Meanwhile,the reported tomography sensors usually have regular arrangement,which forms a nonuniform sensitivity matrix and the region of interest(ROI)is detected unevenly.In this work,we propose an optimization method based on uniformity coefficient and genetic algorithm(GA).We hope our method can provide an optimized sensor configuration that has a uniform sensitivity matrix and improved reconstruction performance.Methods Sensitivity matrix relates the practical distribution to the numerous projections,which is important for image reconstruction.It is well recognized that uniform sensitivity matrix promises improved reconstruction performance.While the reconstructed images have large error when the matrix has low uniformity.In this work,uniformity coefficient is introduced to represent the uniformity of the matrix.Meanwhile,we assume that the uniformity coefficient is directly related to the quality of image reconstruction,namely,lower uniformity coefficient leads to improved reconstruction performance,and larger value leads to deteriorated performance.The optimization procedure mainly includes the following steps.Firstly,reconstruction with 60 configurations and 10 distributions are implemented to verify the effectiveness of the uniformity coeffi

关 键 词：成像系统 配置优化 扇形光束激光器 遗传算法 光学层析成像 Landweber重建算法 

分 类 号：TP317.4[自动化与计算机技术—计算机软件与理论]