电子学报 ›› 2020, Vol. 48 ›› Issue (10): 1976-1982.DOI: 10.3969/j.issn.0372-2112.2020.10.015

• 学术论文 • 上一篇    下一篇

基于轮廓先验约束的复杂异形工件CT成像方法研究

樊亚红, 刘宾, 陈平, 潘晋孝, 李毅红   

  1. 中北大学信息探测与处理山西省重点实验室, 山西太原 030051
  • 收稿日期:2019-09-27 修回日期:2020-05-19 出版日期:2020-10-25
    • 通讯作者:
    • 陈平
    • 作者简介:
    • 樊亚红 女.1993年5月出生,山西长治人.现为中北大学信息与通信工程学院硕士研究生,研究方向为图像处理、CT重建.E-mail:fancynuc@163.com
      刘宾 男.1979年5月出生,山东济宁人.中北大学信息与通信工程学院副教授,硕士生导师,主要研究方向为光电信息处理、数字图像处理、信息重建等.E-mail:liubin414605032@163.com
      潘晋孝 男.1967年1月出生,山西万荣人.中北大学理学院教授,博士生导师,主要研究方向为信号与信息处理、CT重建等.E-mail:panjx@nuc.edu.cn
      李毅红 女.1983年2月出生,山西临汾人.中北大学理学院副教授,硕士生导师,主要研究方向为工程中的数学问题、CT重建等.E-mail:liyihong0227@163.com
    • 基金资助:
    • 国家自然科学基金 (No.61801437,No.61871351,No.61971381); 山西省自然科学基金 (No.201801D221206)

Research on CT Imaging Method of Complex Shaped Workpiece Based on Contour Prior Constraint

FAN Ya-hong, LIU Bin, CHEN Ping, PAN Jin-xiao, LI Yi-hong   

  1. Shanxi Key Laboratory of Signal Capturing&Processing, North University of China, Taiyuan, Shanxi 030051, China
  • Received:2019-09-27 Revised:2020-05-19 Online:2020-10-25 Published:2020-10-25

摘要: 在X射线CT成像检测系统中,复杂异形工件由于结构复杂,散射、硬化等现象较严重,而且在部分投影角度上,由于在射线透照方向上的有效厚度差异大,固定能量的射线剂量与厚度不匹配,投影数据质量较差,传统的CT重建算法得到的重建图像质量低,边缘模糊,无法获取工件的完整轮廓信息.为此文章研究了一种基于轮廓先验约束的复杂异形工件CT成像方法.首先利用双目立体视觉技术获取工件的轮廓信息,根据双目坐标系与CT坐标系间的空间位置关系完成先验图像的配准;然后将轮廓先验纳入到CT重建过程中并结合TV正则化进行轮廓约束重建.实验结果表明,该方法能够有效地抑制伪影和噪声,保留重建图像的边缘,改善重建图像质量,有助于提高复杂异形工件缺陷检测的可靠性.

关键词: X射线成像, 复杂结构件, 轮廓约束, 先验信息

Abstract: In the X-ray CT imaging inspection system,due to the complicated structure of complex shaped workpieces,scattering,hardening and other phenomena are more serious.At some projection angles,due to the large difference in effective thickness in the ray transillumination direction,the fixed energy ray dose does not match the thickness,the quality of the projection data is poor,the reconstructed image obtained by the traditional CT reconstruction algorithm is of low quality,the edges are blurred,and the complete contour information of the workpiece cannot be obtained.In this paper,a CT imaging method for complex shaped workpieces based on contour prior constraints is studied.Firstly,the binocular stereo vision technology is used to obtain the contour information of the workpiece,and the registration of the a priori image is completed according to the spatial positional relationship between the binocular coordinate system and the CT coordinate system.The contour prior is then incorporated into the CT reconstruction process and contour constrained reconstruction is performed in conjunction with TV (Total-variation) regularization.The experimental results show that the proposed method can effectively suppress artifacts and noise,preserve the edges of reconstructed images,improve the quality of reconstructed images,and improve the reliability of defect detection of complex shaped workpieces.

Key words: X-ray imaging, complex structural parts, contour constraint, prior information

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