Posterior-Variance-Based Error Quantification for Inverse Problems in Imaging

التفاصيل البيبلوغرافية
العنوان: Posterior-Variance-Based Error Quantification for Inverse Problems in Imaging
المؤلفون: Narnhofer, Dominik, Habring, Andreas, Holler, Martin, Pock, Thomas
سنة النشر: 2022
المجموعة: Computer Science
Mathematics
مصطلحات موضوعية: Computer Science - Computer Vision and Pattern Recognition, Mathematics - Probability, 68U10, 62F15, 65C40, 65C60, 65J22
الوصف: In this work, a method for obtaining pixel-wise error bounds in Bayesian regularization of inverse imaging problems is introduced. The proposed method employs estimates of the posterior variance together with techniques from conformal prediction in order to obtain coverage guarantees for the error bounds, without making any assumption on the underlying data distribution. It is generally applicable to Bayesian regularization approaches, independent, e.g., of the concrete choice of the prior. Furthermore, the coverage guarantees can also be obtained in case only approximate sampling from the posterior is possible. With this in particular, the proposed framework is able to incorporate any learned prior in a black-box manner. Guaranteed coverage without assumptions on the underlying distributions is only achievable since the magnitude of the error bounds is, in general, unknown in advance. Nevertheless, experiments with multiple regularization approaches presented in the paper confirm that in practice, the obtained error bounds are rather tight. For realizing the numerical experiments, also a novel primal-dual Langevin algorithm for sampling from non-smooth distributions is introduced in this work.
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2212.12499
رقم الأكسشن: edsarx.2212.12499
قاعدة البيانات: arXiv