基于多层平面折射模型与多投影中心模型的光场相机水下标定  

Underwater Light Field Camera Calibration Based on Multi-Layer Flat Refractive Model and Multi-Projection-Center Model

作　　者：张晓强 钟良涛 冷齐齐 冉令燕 楚红雨[1] Zhang Xiaoqiang;Zhong Liangtao;Leng Qiqi;Ran Lingyan;Chu Hongyu(School of Information Engineering,Southwest University of Science and Technology,Mianyang 621000,Sichuan,China;School of Computer Science,Northwestern Polytechnical University,Xi'an 710129,Shaanxi,China)

机构地区：[1]西南科技大学信息工程学院,四川绵阳621000 [2]西北工业大学计算机学院,陕西西安710129

出　　处：《光学学报》2022年第12期220-228,共9页Acta Optica Sinica

基　　金：国家自然科学基金(61902322);四川省科技计划项目(2019YJ0325);西南科技大学博士基金项目(19zx7123);中国民航大学民航航空器适航审定技术重点实验室开放基金(SH2020112706)。

摘　　要：现有光场相机水下标定方法的缺乏限制了光场成像技术在水下等折射场景中的应用。针对这一问题,分别基于多层平面折射模型与多投影中心模型对典型水下场景中光场相机的场景光路与相机光路进行建模,并对相应水下标定参数进行估计。利用平面折射几何约束对光场相机的水下标定参数进行线性初始化估计,并在考虑真实光场相机内部光路畸变的条件下,基于最小化重投影误差对水下标定参数进行非线性优化。设计了模拟场景与真实水下场景的定量标定实验对所提方法的有效性进行验证。结果表明,所提方法能够较精确地对水下标定参数进行估计。在多次真实水下场景实验中,折射面法向量方向误差均小于0.8°,折射面距离误差均小于3%。定量对比实验结果表明,相较单视水下标定方法,由于所提方法利用了光场相机的多视特性,故其标定结果与真实值更为接近。The lack of calibration methods for the underwater light field camera restricts the applications of light field imaging technologies in underwater and other refractive scenes.Aiming at the above problem,the ray paths of the scene and those inside the camera in typical underwater scenes are modeled based on the multi-layer flat refractive model and the multi-projection-center model,and the corresponding underwater calibration parameters are estimated.The underwater calibration parameters of the light field camera are linearly initialized by using the flat refractive geometric constraints.Considering the internal ray path distortion in the real light field camera,the underwater calibration parameters are optimized nonlinearly by minimizing the reprojection error.Quantitative calibration experiments of simulated scenes and real underwater scenes are designed to verify the effectiveness of the proposed method.The results show that the proposed method can estimate the underwater calibration parameters accurately.In multiple real underwater scene experiments,the direction errors of the normal vectors of the refraction surfaces are all less than 0.8°and the distance errors of the refraction surfaces are all less than 3%.The quantitative comparison experimental results show that,compared with the single-view underwater calibration method,the proposed method makes use of the multi-view characteristics of the light field camera,so the calibration results are closer to the real values.

关 键 词：机器视觉 标定 水下相机标定 光场 光场相机 平面折射几何 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]