利用单幅投影图像重建不对称客体密度分布

摘要

Due to the limited number of views in high-energy X-ray radiography, the density reconstruction for asymmetric objects from a single radiograph is studied. The approach proposed can make explicit use of model-based information concerning the symmetric and asymmetric information from the radiograph to compose the other rotational views in a more exact fashion. The three dimension program for the density reconstruction is developed based on total variation and algebraic reconstruction techniques. Numerical simulations show the impact on the accuracy of density reconstruction by varying the number of the radiograph-ic views.%针对高能X射线照相系统成像数目受到限制的现状,研究了利用单幅投影图像重建具有部分不对称性结构物体的密度分布的方法,提出了利用图像的对称和不对称信息,并结合先验信息构造多角度投影图像的方法.研制了基于全变分和代数重建技术的3维密度重建程序,并通过仿真实验,定量给出了图像数目对密度重建精度的影响规律.数值仿真结果表明:当投影图像数目达到一定值后,重建密度误差的变化变得很缓慢,重建密度的误差随图像数目的增加而减小,在只有少数投影图像的密度重建时,误差减小较为明显,从性价比的角度来说,10幅图像最佳.