基于加权平均的工业CT旋转中心校正方法

吕振涛; 桂志国; 刘祎; 张鹏程

doi:10.15953/j.1004-4140.2021.30.05.01

基于加权平均的工业CT旋转中心校正方法

中北大学信息与通信工程学院, 太原 030051

基金项目:

国家自然科学基金（复杂薄壁铸件射线成像及层析技术研究（61801438））；高等学校科技创新项目（复杂薄壁铸件缺陷自动检测及识别技术研究（2020L0282））。

详细信息

作者简介:
吕振涛,男,中北大学信息与通信工程专业硕士,主要从事工业X射线成像、无损检测、CT重建等方面的研究,E-mail:695796542@qq.com;桂志国^*,男,中北大学教授,主要从事三维CT理论与工程应用、医学图像处理与重建等方面的研究,E-mail:guizhiguo@nuc.edu.cn。

中图分类号: O242;TP391.41
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出版历程
- 收稿日期: 2021-04-16
- 网络出版日期: 2021-09-22

Industrial CT Rotation Center Calibration Method Based on Weighted Average

Collage of Information and Telecommunication, North University of China, Taiyuan 030051, China

摘要

摘要: 旋转中心的精确定位是重建高质量CT图像的一个重要条件。本文提出一种基于加权平均的旋转中心校正方法，该方法首先将投影正弦图以180°为界限分成两组投影数据，计算出这两组投影数据的互相关系数及其对应的探测器探元坐标，然后使用最大与次最大的互相关系数对探测器探元坐标值进行加权平均得到实际旋转中心坐标。本文所提算法完全基于原始投影数据，无需确定CT测量的几何参数，不用提前对投影数据进行插值运算就可以将旋转中心精确到亚像素级，精度更高，实现简单。
- CT图像 /
- 旋转中心校正 /
- 加权平均 /
- 正弦图 /
- 互相关
Abstract: The precise positioning of the rotation center is an important condition for reconstructing high-quality CT images. In this paper we propose a center rotation calibration method based on weighted average. First we divide the projection sinogram into two sets of projection data by limit of 180°, thus we can figure out the calibration coefficient of the two sets of projection data and their corresponding detector probes. Then we use the maximum and the sub-maximal cross-correlation coefficients to obtain the actual rotation center coordinates by weighting average the coordinate values of the detector elements. The algorithm proposed in this paper is completely based on the original projection data. There is no need to determine the geometric parameters of the CT measurement, and we can acquire sub-pixel level accuracy of the rotation center without interpolating the projection data in advance. The accuracy is higher while the implementation is quite simple.
- CT image /
- rotation center /
- weighted average /
- sinogram /
- cross-correlation

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参考文献(15)

[1]	马超. 无损检测技术及应用[J]. 影像科学与光化学, 2020, 38(1):46-51. MA C. Non-destructive testing technology and application[J]. Imaging Science and Photochemistry, 2020, 38(1):46-51. (in Chinese).
[2]	陈思宇. 工业锥束CT图像环状及硬化伪影校正技术研究[D]. 郑州:解放军信息工程大学, 2016. CHEN S Y. Research on correction technology of ring and hardening artifacts in industrial cone- beam CT images[D]. Zhengzhou:The PLA Information Engineering University, 2016. (in Chinese).
[3]	林强, 宋鑫. 偏置扫描模式下工业CT系统转台旋转中心确定方法[C]//第十五届中国体视学与图像分析学术会议论文集, 2017:64. LIN Q, SONG X. Method of determining rotation center of industrial CT system turntable in offset scan mode[C]//Proceedings of the 15^th Chinese Conference on Stereology and Image Analysis, 2017:64. (in Chinese).
[4]	万犇, 贾昀达, 王宏晔, 等. 基于图像重建的CT系统参数标定与成像模型[J]. 实验科学与技术, 2019, 17(1):17-22 , 45. WAN B, JIA Y D, WANG H Y, et al. Parameter calibration and imaging model of CT system based on image reconstruction[J]. Experiment Science and Technology, 2019, 17(1):17-22, 45. (in Chinese).
[5]	赵雨晴, 丛长虹, 胡春红, 等. 基于正弦图的投影旋转中心校正方法[J]. 图学学报, 2017, 38(4):596-602. ZHAO Y Q, CONG C H, HU C H, et al. Correction method of projection rotation center based on sinogram[J]. Journal of Graphics, 2017, 38(4):596-602. (in Chinese).
[6]	刘明进. 工业CT系统旋转中心定位方法研究[D]. 重庆:重庆大学, 2014. LIU M J. Research on positioning method of rotation center of industrial CT system[D]. Chongqing:Chongqing University, 2014. (in Chinese).
[7]	LIU T, MALCOLM A A. Comparison between four methods for central ray determination with wire phantoms in micro-computed-tomography systems[J]. Optical Engineering, 2006, 45(6):711-725.
[8]	YANG M, GAO H D, LI X D, et al. A new method to determine the center of rotation shift in 2D-CT scanning system using image cross correlation[J]. NDT and E International, 2012, 46:48-54.
[9]	李保磊, 傅健, 魏东波, 等. 工业计算机断层成像系统转台旋转中心的确定[J]. 航空动力学报, 2009, 24(7):1544-1548. LI B L, FU J, WEI D B, et al. Determination of rotation center in industrial computed tomography system[J]. Journal of Aerospace Power, 2009, 24(7):1544-1548. (in Chinese).
[10]	孟凡勇, 李忠传, 杨民, 等. 基于投影原始数据的CT旋转中心精确确定方法[C]//第十三届中国体视学与图像分析学术会议论文集, 2013:390-395. MENG F Y, LI Z C, YANG M, et al. Accurate determination method of CT rotation center based on projection raw data[C]//Proceedings of the 13^th Chinese Conference on Stereology and Image Analysis, 2013 :390-395. (in Chinese).
[11]	刘欢, 陈俊彪, 宋小鹏, 等. 基于统计平均的旋转中心确定方法[J]. 测试技术学报, 2019, 33(6):498-502. LIU H, CHEN J B, SONG X P, et al. Method for determining the center of rotation based on statistical average[J]. Journal of Test and Measurement Technology, 2019, 33(6):498-502. (in Chinese).
[12]	傅健, 刘振中. X射线显微镜纳米CT旋转中心随机偏移的校正[J]. 光学精密工程, 2015, 23(10):645-651. FU J, LIU Z Z. Correction of random offset of rotation center of nano CT in X-ray Microscope[J]. Optical and Precision Engineering, 2015, 23(10):645-651. (in Chinese).
[13]	李保磊, 傅健, 黄巧珍, 等. 一种基于正弦图的工业CT系统转台旋转中心自动确定方法[J]. 航空学报, 2009, 30(7):1341-1345. LI B L, FU J, HUANG Q Z, et al. A method for automatically determining the rotation center of industrial CT system turntable based on sinogram[J]. Acta Aeronautica et Astronautica Sinica, 2009, 30(7):1341-1345. (in Chinese).
[14]	罗福婷, 郑继明, 张亚, 等. 运用投影正弦图和点扩展函数法确定CT系统旋转中心[J]. 科技与创新, 2018, (5):38-41. LUO F T, ZHENG J M, ZHANG Y, et al. Determining the center of rotation of CT system by using projected sinogram and point spread function method[J]. Science and Technology & Innovation, 2018 , (5):38-41. (in Chinese).
[15]	罗泽峰, 余娇, 崔文超. 椒盐噪声去除方法分析及对比研究[J]. 信息通信, 2018, (7):38-41. LUO Z F, YU J, CUI W C. Analysis and comparative study on the methods of removal of salt and pepper noise[J]. Information and Communication, 2018 , (7):38-41. (in Chinese).