基于光场成像的视差与深度的数值关系研究

Study on Numerical Relationship Between Disparity and Depth Based on Light Field Imaging

光场成像能同时记录光线的强度与方向信息,且具有深度估计的能力。然而,目前的方法仅进行视差估计,较少方法将光场视差转换为绝对深度,以实现三维测量。因此,本文通过对微透镜阵列光场相机的三维成像原理进行分析,建立光场视差与绝对深度之间的数值转换关系。首先,通过对光场成像中的视差原理进行理论分析得到视差与等效基线之间的关系。其次,对微透镜阵列光场相机的成像原理进行分析后得到等效基线与相机结构参数之间的关系,并结合视差与高斯成像公式得到视差与绝对深度之间的数值转换关系。最后,通过标定光场相机以及搭建试验平台验证该转换关系的有效性。试验结果表明,该转换关系能准确地将视差转换为绝对深度,并获得了试验标准件的外形尺寸。

Lightfield imaging can simultaneously record the intensity and direction information of rays and has the ability of depth estimation.However,the current methods only achieve disparity estimation,and few methods convert the disparity to absolute depth to achieve three-dimensional measurement.Therefore,this paper theoretically analyzes the three-dimensional imaging principle of lenslet-based lightfield cameras and establishes the numerical conversion relationship between disparity and absolute depth of lenslet-based lightfield cameras.Firstly,the relationship between the disparity and equivalent baseline is obtained by the theoretical analysis of the disparity principle in lightfield imaging.Secondly,the imaging principle of lenslet-based lightfield cameras is analyzed to obtain the relationship between the equivalent baseline and the camera’s internal parameters,and the numerical conversion relationship between disparity and absolute depth is obtained by combining the disparity and Gaussian imaging formula.Finally,the validity of the conversion relationship is verified by calibrating the lightfield camera and building an experimental platform.Experimental results show that this relationship can convert disparity into absolute depth and obtain high-precision results.