光场相机结构参数及装配误差标定方法  

Calibration Method for Structural Parameters and Assembly Error of Light Field Camera

作　　者：袁索超 李铭 达争尚[1] Yuan Suochao;Li Ming;Da Zhengshang(Xi'an Institute of Optics and Precision Mechanics,Chinese Academy of Sciences,Xi'an,Shanxi 710119,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院西安光学精密机械研究所,陕西西安710119 [2]中国科学院大学,北京100049

出　　处：《中国激光》2021年第20期47-54,共8页Chinese Journal of Lasers

基　　金：国家自然科学基金(U1930118)。

摘　　要：在光场相机的各种应用中,光场的解码和重构都是必不可少的环节。光场相机的结构参数和装配误差的标定对于光场的解码和重构精度至关重要。鉴于此,提出基于光学检测原理的光场相机标定方法,标定过程分为有主镜标定和无主镜标定两部分。结构参数的标定是在有主镜情形下完成的,利用微透镜对主镜出瞳成像的关系构建结构参数标定模型,标定过程中采用均匀光照明主镜光瞳来获得标定图像。装配误差的标定是在无主镜情形下完成的,利用微透镜对无穷远物点的成像特性构建装配误差标定模型,标定过程中采用准直光直接照射微透镜阵列来获得标定图像。采用所提方法对自装配的光场相机进行标定实验,实验结果验证标定模型的正确性和标定方法的可行性。Objective A light field camera that is capable of capturing four-dimensional light field information through a single shot can be realized by inserting a microlens array in front of the sensor of a traditional camera.It has great potential to play important roles in many applications such as 3D measurement,flow field velocimetry,and wavefront sensing.To obtain the image information,the captured light-field information shall be decoded.The decoding process is largely based on the structural parameters of the light field camera,including the distance between the microlens array and sensor and the pitch of the microlens array.Because of the errors introduced during the manufacturing and assembling processes,using the nominal values of these parameters are not recommended;calibration of the true values and assembly errors are desired.Several studies have been conducted on the calibration of light field cameras.However,most of these studies follow the framework of the calibration method used for traditional cameras,where a complicated imaging model is built and the unknown parameters are searched using an optimization algorithm.The complexity of procedures in such methods makes them difficult to implement.Based on optical test principles,a new calibration method using simpler calibration models is proposed,which enables fast calibration.Methods The proposed calibration method comprises two parts:calibration with the main lens and calibration without the main lens.The calibrations of structural parameters are accomplished when the main lens is mounted,and the calibration model is based on the relation that the exit pupil of the main lens is imaged by the microlens.A uniform light source is used to illuminate the pupil of the main lens to obtain calibration images.The distance between the microlens array and sensor and the pitch of the microlens array are treated as two optimized variables of an optimization model and are calculated by searching the optimal values.The calibration of assembly errors is accomplished when

关 键 词：测量 计算成像 光场相机 结构参数 装配误差 标定 光学检测 

分 类 号：TN206[电子电信—物理电子学]