基于新型混合滤波函数的滤波反投影重建算法  

Filtered Back-projection Reconstruction Algorithm Based on New Hybrid Filter Function

作　　者：张浩杰 王明泉[1] 程志勇 姜康 张曼 ZHANG Hao-jie;WANG Ming-quan;CHENG Zhi-yong;JIANG Kang;ZHANG Man(School of Information and Communication Engineering,North University of China,Taiyuan 030051,China)

机构地区：[1]中北大学信息与通信学院,太原030051

出　　处：《自动化与仪表》2020年第11期94-97,共4页Automation & Instrumentation

基　　金：国家重大科学仪器设备开发专项(2013YQ240803)。

摘　　要：对于X射线计算机断层成像(computed tomography,CT)图像重建FBP算法中,滤波函数的选取将直接影响重建结果的优劣,通常采用的矩形滤波函数会导致明显的Gibbs现象,影响重建图像的质量。为了能使图像重建质量更优,该文针对滤波函数的选取进行研究,在分析R-L、NEW、S-L及其他混合滤波函数的基础上,再结合混合滤波的理论,引入一种新的混合滤波函数即NEW-SL滤波函数。通过数值仿真,分析比较新型混合滤波函数NEW-SL和其它滤波函数R-L、NEW、S-L等重建图像的灰度曲线、归一化均方误差和归一化平均误差参数,结果表明,采用NEW-SL滤波函数能使重建图像的灰度曲线更加平滑、归一化均方误差达到0.2960、归一化平均误差达到0.5102,更好地抑制图像重建的振荡,使重建后的图像更加平滑。For X-ray computed tomography(CT)image reconstruction FBP algorithm,the selection of the filter function will directly affect the quality of the reconstruction result.The rectangular filter function usually used will cause obvious Gibbs phenomenon and affect the quality of the reconstructed image.In order to make the image reconstruction quality better,this paper studies the selection of filter functions.Based on the analysis of RL,NEW,SL,and other mixed filter functions,combined with the theory of hybrid filtering,a new hybrid filter function is introduced,namely NEW-SL filter function.Through numerical simulation,the gray curve,normalized mean square error,and normalized average error parameters of the reconstructed image,such as the new hybrid filter function NEW-SL and other filter functions RL,NEW,and SL,are compared.The results show that The SL filter function can make the gray curve of the reconstructed image smoother,the normalized mean square error reaches 0.2960,and the normalized average error reaches 0.5102,which can better suppress the oscillation of image reconstruction and make the reconstructed image smoother.

关 键 词：FBP算法 滤波函数 混合滤波 CT重建 灰度值 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]