Resilient Practical Test-Time Adaptation: Soft Batch Normalization Alignment and Entropy-driven Memory Bank
Xingzhi Zhou, Zhiliang Tian, Ka Chun Cheung, Simon See, Nevin L. Zhang
TL;DR
This paper tackles test-time domain adaptation under continual target-domain shifts and temporal correlations by proposing ResiTTA, a three-component framework. It combines Resilient Batch Normalization (ResiBN) to stabilize statistics with soft alignment, an Entropy-Driven Memory Bank (EntroBank) to curate high-quality memory samples, and a teacher-student self-training scheme to periodically adapt the model using memory data. ResiBN uses exponential updates of target statistics and $W_2^2$-based soft alignment between target and source BN statistics, while EntroBank manages timeliness, long-persisted over-confident samples, and sample uncertainty to maintain data quality. Empirical results on CIFAR10-C, CIFAR100-C, and ImageNet-C show state-of-the-art performance under practical test-time adaptation, with substantial improvements in average error over strong baselines and robustness across corruption types.
Abstract
Test-time domain adaptation effectively adjusts the source domain model to accommodate unseen domain shifts in a target domain during inference. However, the model performance can be significantly impaired by continuous distribution changes in the target domain and non-independent and identically distributed (non-i.i.d.) test samples often encountered in practical scenarios. While existing memory bank methodologies use memory to store samples and mitigate non-i.i.d. effects, they do not inherently prevent potential model degradation. To address this issue, we propose a resilient practical test-time adaptation (ResiTTA) method focused on parameter resilience and data quality. Specifically, we develop a resilient batch normalization with estimation on normalization statistics and soft alignments to mitigate overfitting and model degradation. We use an entropy-driven memory bank that accounts for timeliness, the persistence of over-confident samples, and sample uncertainty for high-quality data in adaptation. Our framework periodically adapts the source domain model using a teacher-student model through a self-training loss on the memory samples, incorporating soft alignment losses on batch normalization. We empirically validate ResiTTA across various benchmark datasets, demonstrating state-of-the-art performance.
