激光反射断层成像相位恢复方法

Research of Phase Retrieval Method in Laser Reflective Tomography Imaging

针对激光反射断层成像过程中存在目标的平动和抖动所产生的旋转中心偏移导致重建图像错位形成伪影的问题,提出基于相位恢复技术的改进误差下降算法.该方法通过光强反复迭代得到相位分布,获得重构目标丢失的相位信息,通过增加初始约束条件以及空间域和频域的限制有效改善算法的收敛性.运用改进的误差下降算法,有效改善了相位恢复方法容易陷入局部极小解的问题,获得了优化的重构图像.仿真实验表明,三组投影数据重建图像的平均相对均方误差由0.774下降为0.551,能够有效消除图像重建伪影.外场实验结果表明此方法使激光反射断层成像系统分辨率得到有效改善.

The moving and jitter of the target will lead to the rotation of the center of rotation in the process of laser reflection tomography.This will lead to reconstruction image dislocation and artifact,a modified error reduction algorithm based on phase recovery technology was proposed.Firstly,the phase information of reconstructed target was obtained through iterative iteration of light intensity.In addition,the convergence of algorithm was also effectively improved by increasing the initial constraints and the constraints in the spatial and frequency domains.This method can effectively improve the easy to fall into the local minima problem and phase recovery method for image reconstruction optimization is obtained.The simulation experiments show that the mean square error of the three sets of reconstructed images is reduced from 0.774 to 0.551,and the image reconstruction artifact can be effectively eliminated.The experimental results also show that the resolution of the laser reflective tomography system is improved.