光场分层成像系统的重聚焦标定方法

Refocusing Calibration Method for Light Field Optical Sectioning Tomography System

为根据参数精确获取分层位置的重聚焦像,提出了基于阶梯尺的标定方法.用光场相机拍摄阶梯标尺,利用重聚焦技术获得图像序列,使用点锐度评价函数计算图像序列各刻度面最清晰图像,完成重聚焦参数的标定.对标定结果进行评价,采用刃边法计算重聚焦图像的高斯离焦参数,阶梯标尺比刻度标尺标定方法减小25%以上,可以有效提高光场相机重聚焦的准确度.进行分层成像实验,对比两种标定方法下的分层重聚焦图像,验证了阶梯标尺标定的重聚焦结果更清晰,适用于光场分层成像系统.

In order to accurately obtain the refocusing image of the depth position according to the parameter,a calibration method based on the step ruler is proposed.Taking the original image by the light field camera,the image sequence is obtained by the refocusing technique,and the scale surface of the image sequence is calculated by the definition evaluation function,to find the clearest image,complete calibration of the refocusing parameter.Evaluating the calibration results,the knife-edge method is used to calculate the Gaussian defocusing parameter of the refocused image.The value of this method is reduced by more than 25%compared with the method of the scale ruler,which can effectively improve the accuracy of refocusing of the light field camera.The sectioning imaging experiment was carried out,and the sectioning refocusing images under the two calibration methods were compared to verify that the refocusing results of the step ruler calibration are clearer and suitable for the light field optical sectioning tomography system.