arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2203.01030math.NAcs.NAeess.IVstat.AP
收藏

海底管道贝叶斯CT重建的结构高斯先验

Structural Gaussian Priors for Bayesian CT reconstruction of Subsea Pipes

Silja L. Christensen, Nicolai A. B. Riis, Felipe Uribe, Jakob S. Jørgensen

摘要:

X射线计算机断层扫描(CT)的无损检测(NDT)应用是通过2D横截面扫描检查运行中的海底管道。由于海底环境具有挑战性,数据采集既耗时又昂贵。减少扫描中的投影数量可以节省时间和成本,但如果使用传统的重建方法,则会损害重建质量。在这项工作中,我们采取贝叶斯方法进行CT重建,并专注于设计一个有效的利用现有的结构信息的管道几何形状。我们提出了一类新的结构高斯先验,通过高斯马尔可夫随机场(GMRF)先验,结合全局规律性的独立高斯先验的重建图像的不同区域中执行预期的材料属性。数值实验与合成和真实数据表明,所提出的结构高斯先验可以减少伪影和增强对比度的重建相比,只使用一个全球的GMRF先验或根本没有先验。我们展示了如何得到的后验分布可以有效地采样,即使是大规模的图像,这是必不可少的实际无损检测应用。

英文摘要:

A non-destructive testing (NDT) application of X-ray computed tomography (CT) is inspection of subsea pipes in operation via 2D cross-sectional scans. Data acquisition is time-consuming and costly due to the challenging subsea environment. Reducing the number of projections in a scan can yield time and cost savings, but compromises the reconstruction quality, if conventional reconstruction methods are used. In this work we take a Bayesian approach to CT reconstruction and focus on designing an effective prior to make use of available structural information about the pipe geometry. We propose a new class of structural Gaussian priors to enforce expected material properties in different regions of the reconstructed image based on independent Gaussian priors in combination with global regularity through a Gaussian Markov Random Field (GMRF) prior. Numerical experiments with synthetic and real data show that the proposed structural Gaussian prior can reduce artifacts and enhance contrast in the reconstruction compared to using only a global GMRF prior or no prior at all. We show how the resulting posterior distribution can be efficiently sampled even for large-scale images, which is essential for practical NDT applications.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑