基于像素采样不足的伪迹处理方法  

Anti-alias Processing of Cone Beam CT Reconstruction

作　　者：莫会云[1] 潘晋孝[1] 

机构地区：[1]中北大学理学院电子测试技术国家重点实验室,太原030051

出　　处：《中国体视学与图像分析》2008年第2期129-133,共5页Chinese Journal of Stereology and Image Analysis

基　　金：国家自然基金资助项目(No.60532080)

摘　　要：在实际的三维锥束CT重建中,受扫描结构的限制,当连续X射线穿过物体时,像素对射线的采样间隔不能满足Nyqust采样定理,这样通道信号产生混叠,使得重建图像出现伪迹。本论文针对这一问题,在用splatting算法[1-2]计算代数重建算法权系数的基础上,分析了伪迹产生的原因并对对应的内插函数作了适当的变换,提出了适用于3-D锥束圆轨迹CT扫描系统的去伪处理方法。结果表明,经过去伪处理后,重建图像的分辨率明显提高。In practical 3-D cone beam CT reconstruction, for the restriction of scanning structure, the sampling frequency of pixel to ray can＇t satisfy the Nyqust sampling theorem, then will produce composite signals, and make the streak artifacts in reconstruction image. In order to solve this problem, the condition of alias signals appearance is analyzed and a suitable transform of interpolating function based on utilizing the splatting algorithm is proposed, so as to evaluate the weight coefficient of algebraic reconstruction arithmetic;Finally an anti-alias processing method applied for circumrotatory CT system based on circular trace is given. The result shows that through anti-alias processing, the special resolution of reconstructed image is enhanced obviously.

关 键 词：去伪处理 锥束扫描 内插函数 伪迹 

分 类 号：TN911.7[电子电信—通信与信息系统]