arXiv Computer Vision

Classification-oriented adaptive sensing via posterior sampling

The paper proposes a classification-oriented adaptive sensing method that uses posterior sampling from diffusion models. It leverages the closed-form posterior covariance of a class-conditional Gaussian mixture model to separate within-class and between-class uncertainty, estimating these terms from diffusion posterior samples via calibrated soft classifier outputs. Experiments on MNIST and CIFAR-10 demonstrate that this approach can achieve better classification accuracy for a given measurement cost compared to reconstruction-oriented methods, while also quantifying the associated reconstruction quality.

arXiv Computer Vision
Sep 21

How Many Posterior Samples? Calibrated Stopping for Adaptive Sensing

The paper investigates how to decide when to stop collecting posterior samples in classification‑oriented adaptive sensing. It shows that a simple threshold‑based plug‑in rule does not guarantee the desired confidence level, and proposes calibrated fixed‑sample and finite‑horizon sequential stopping rules that control the false‑declaration probability. Experiments on MNIST demonstrate that the sequential rule can reduce sensing cost the most, and that a curtailment strategy can save up to 62% of posterior samples while maintaining accuracy.

By Vincent Corlay, Andriy Enttsel
arXiv Statistics ML
6d ago

Learning to Replace MCMC in Split-Gibbs Diffusion Posterior Sampling via Deep Unfolding

The paper introduces a learning-based approach to replace the MCMC step in split-Gibbs diffusion posterior sampling. By reformulating both Gibbs updates as Gaussian denoising problems, the method uses ODE diffusion for the prior step with a pretrained denoiser and a lightweight deep-unfolded network for the likelihood step. Experiments on nonlinear phase retrieval show that this alternative reduces likelihood-update cost while maintaining effectiveness compared to MCMC-based split Gibbs.

By Yi Zhang, Rui Guo, Mengchu Xu, Zhaofeng Liu, Yonina C. Eldar
arXiv Machine Learning
Sep 23

FREESIA: Covariance-Aware Posterior Transport for Expressive and Scalable Data Assimilation

The paper introduces FREESIA, a training‑free, covariance‑aware posterior transport method for data assimilation that embeds forecast cross‑covariance into a flow‑based transport to recover unobserved states while preserving non‑Gaussian posterior structure. It combines an observation‑adaptive proposal with posterior correction, providing an asymptotically exact approximation of nonlinear posteriors and a Wasserstein error bound. Experiments on Double‑Well, Lorenz‑96, and Kolmogorov flow demonstrate that FREESIA captures complex posterior structures and achieves up to a 56% reduction in RMSE compared to the best baseline in sparse, nonlinear, non‑injective observation scenarios.

By Shiwei Ni, Yangwen Zhang, Hang Qi, Xiaofei Guan, Lili Ju