由于太赫兹波具有独特的性质,使得太赫兹成像技术成为目前的研究热点。太赫兹层析成像可以获得物体横截面的分布信息并可获得物体的三维重构图像,因此也受到了广泛关注。文中对连续太赫兹层析成像进行了仿真研究。分别使用滤波反投影算法(FBP)和改进的联合代数重建算法(MSART)进行图像重构,并且分析比较了高斯低通滤波(GLPF)以及数学形态学等数字图像处理方法对改善重构图像质量的效果。仿真结果表明:在文中的仿真条件下,使用MSART算法及相应的图像处理方法所需的最少投影方向数可以达到9,与真实成像实验结果相吻合。
Terahertz (THz) radiation has many particular characteristics, which make THz image technology become the hot research area. As the distribution information of the cross section and the 3D reconstruction image of a sample can be obtained, THz computed tomography (CT) also attracts wide extensive attention worldwide. The simulation research was done based on continuous THz CT. The filtered back-projection (FBP) method and the modified simultaneous algebraic reconstruction technique (MSART) method have been utilized to reconstruct cross-section images, and the efficiency of the image processing operations such as the Gaussian low-pass filter (GLPF) and the morphological functions in mathematical morphology like open operation and close operation in improving reconstruction image quality has been compared and analyzed. It can be inferred from the simulation results that the required number of the projection directions using the MSART method and the corresponding image processing operations can only be 9, which is inosculate to the real imaging experiment results.