基于遗传-反卷积算法的飞行时间测距相机非视域成像  

Reconstruction of Non-Line-of-Sight Depth Data Using Genetic Algorithm-Lucy-Richardson Based on Time of Flight Camera

作　　者：方宇杰 王霞[1,2,3] 苏秉华 Fang Yujie;Wang Xia;Su Binghua(Key Laboratory of Optoelectronic Imaging Technology and System,Ministry of Education,School of Optics and Photonics,Beijing Institute of Technology,Beijing 100081,China;Beijing Institute of Technology,Zhuhai 519085,Guangdong,China;Key Laboratory of Intelligent Detection in Complex Environment of Aerospace,Land,and Sea,Zhuhai 519085,Guangdong,China)

机构地区：[1]北京理工大学光电学院光电成像技术与系统教育部重点实验室,北京100081 [2]北京理工大学珠海学院,广东珠海519085 [3]“天临空地海”复杂环境智能探测重点实验室,广东珠海519085

出　　处：《光学学报》2023年第21期79-89,共11页Acta Optica Sinica

基　　金：广东省普通高校重点领域专项(2021ZDZX3012);广东省重点领域研发计划(2021B0707010001)。

摘　　要：非视域成像是指被测目标在相机探测视场外部,被测目标的光信号需要通过中介面反射后被相机采集,进而实施计算成像的一种技术。针对退化的非视域图像,去除中介面影响而获得清晰目标的过程属于一种光学逆问题。因此,中介面的光学散射特性在逆问题中的模型是一个关键。本文采用光子飞行时间测距(TOF)相机,提出一种非朗伯散射特性中介面的近似数值模型,并通过遗传算法求取,基于所求近似数值解,通过Lucy-Richardson(LR)反卷积实现非视域目标的三维重建。实验中,采用了打磨过的聚丙烯塑料(PP)板和亚克力(PMMA)板作为反射中介面,被测目标为表面形状复杂的石膏雕像、抛光塑料面板和多个目标的自然场景等常见实物,应用所提遗传-反卷积算法对非视域目标进行重构,通过重构前后的主观对比以及均方差的客观数据对比,得出重构后深度图像的均方误差是原始图像均方误差的1/7~1/2,表明了该算法的有效性。Objective The action of implementing computational photography for targets out of the field of view(FOV)such as behind the barrier by a reflective relay surface is defined as non-line-of-sight(NLOS)imaging.NLOS technology has a promising future in the fields of medicine,road safety,and scientific research due to its ability to expand the human's FOV in scenarios where a direct view is impossible to obtain by devices or human eyes.The present NLOS technology mostly includes transient imaging,range-gated imaging,and passive pattern imaging,and they are mostly dedicated to Lambert reflector relay surfaces.However,the materials in common scenarios are usually non-Lambertian reflectors,whose scattering characteristics are random and diverse,with different degradation characteristics of NLOS imaging results.The traditional methods always have complex system structures,slow imaging speeds,and high costs.We propose a new NLOS method based on the time of flight(TOF)camera,which requires lower maintenance costs,indicates higher availability than the transient imaging and range-gated imaging,and can also realize 3D reconstruction compared with the passive pattern.The NLOS 3D imaging can be achieved for the relay surface with non-Lambertian scattering characteristics by the proposed method to provide theoretical references and an experimental basis for the application.Methods The NLOS images collected by the reflective relay surface suffer from serious degradation of which the process is directly determined by the optical scattering characteristics of the relay surface.The following theoretical hypothesis is provided by analyzing the propagation method of the target optical signal(Fig.1).The degraded images are formed from convolution between the clear image and the relay surface with scattering characteristics.As a result,reconstruction for clear images can be realized through the deconvolution of degraded images if scattering characteristics of the relay surface are obtained.Depth imaging can be achieved for the TOF camera

关 键 词：光学数据处理 图像重构 散射后测量 相位测量 

分 类 号：O43[机械工程—光学工程]