arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2207.09147stat.COstat.AP
收藏

保边线性贝叶斯反演的马蹄先验

Horseshoe priors for edge-preserving linear Bayesian inversion

Felipe Uribe, Yiqiu Dong, Per Christian Hansen

摘要:

在许多大规模的反问题中,如计算机断层扫描和图像去模糊,需要描述解中的尖锐边缘。在逆问题的贝叶斯方法中,边缘保持通常使用基于重尾分布的马尔可夫随机场先验来实现。另一个在统计学中很流行的策略是分层收缩先验的应用。该公式的优点在于将先验表示为依赖于被赋予重尾超先验的全局和局部超参数的条件高斯分布。在这项工作中,我们重新审视收缩马蹄事先,并介绍其制定的边缘保持设置。我们讨论了一个抽样框架的基础上的吉布斯采样器来解决由此产生的贝叶斯逆问题的分层制定。特别地,其中一个条件分布是高维高斯分布,其余的是通过使用重尾超先验的尺度混合表示以封闭形式导出的。从成像科学的应用表明,我们的计算过程是能够计算尖锐的边缘保持后点估计减少不确定性。

英文摘要:

In many large-scale inverse problems, such as computed tomography and image deblurring, characterization of sharp edges in the solution is desired. Within the Bayesian approach to inverse problems, edge-preservation is often achieved using Markov random field priors based on heavy-tailed distributions. Another strategy, popular in statistics, is the application of hierarchical shrinkage priors. An advantage of this formulation lies in expressing the prior as a conditionally Gaussian distribution depending of global and local hyperparameters which are endowed with heavy-tailed hyperpriors. In this work, we revisit the shrinkage horseshoe prior and introduce its formulation for edge-preserving settings. We discuss a sampling framework based on the Gibbs sampler to solve the resulting hierarchical formulation of the Bayesian inverse problem. In particular, one of the conditional distributions is high-dimensional Gaussian, and the rest are derived in closed form by using a scale mixture representation of the heavy-tailed hyperpriors. Applications from imaging science show that our computational procedure is able to compute sharp edge-preserving posterior point estimates with reduced uncertainty.

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。

↑