arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2402.09004cs.CVcs.LG
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STAG:结构化测试时梯度对齐用于在线适应

STAG: Structural Test-time Alignment of Gradients for Online Adaptation

Seoul National University, Seoul, Republic of Korea;Division of Artificial Intelligence \& Software, Ewha Womans University, Seoul, Republic of Korea;Microsoft, Redmond, WA, USA;Georgia Institute of Technology, Atlanta, GA, USA

Juhyeon Shin, Yujin Oh, Jonghyun Lee, Saehyung Lee, Minjun Park, Dongjun Lee, Uiwon Hwang, Sungroh Yoon

AI总结:

STAG通过结构化梯度对齐提升在线适应性能,适用于多种架构和归一化方案,在挑战性场景下表现优异。

摘要:

测试时适应(TTA)利用仅有的未标记测试流对预训练模型进行适应,需要实时推理和更新,而无需访问源数据。我们提出了结构化测试时梯度对齐(STAG),一种轻量级的插件增强器,利用始终可用的结构信号:分类器的内在几何结构。STAG通过自我结构熵从分类器权重中推导出类级结构锚点,并在适应过程中通过分析计算前向传递量的预测类熵梯度,并通过余弦相似度损失将其对齐到相应的锚点。这种闭合形式的设计导致几乎零的内存和延迟开销,并且仅需在基础模型之上进行额外的反向传播。在损坏图像分类和持续语义分割中,STAG为强TTA基线在CNN和Transformer架构上提供广泛适用的性能提升,无论底层归一化方案如何,特别是在具有挑战性的在线条件下,如不平衡标签偏移、单样本适应、混合损坏流和长时间连续TTA时,具有特别大的提升。

英文摘要:

Test-Time Adaptation (TTA) adapts pre-trained models using only unlabeled test streams, requiring real-time inference and update without access to source data. We propose StructuralTest-time Alignment of Gradients (STAG), a lightweight plug-in enhancer that exploits an always-available structural signal: the classifier's intrinsic geometry. STAG derives class-wise structural anchors from classifier weights via self-structural entropy, and during adaptation analytically computes the predicted-class entropy gradient from forward-pass quantities, aligning it to the corresponding anchor with a cosine-similarity loss. This closed-form design incurs near-zero memory and latency overhead and requires no additional backpropagation beyond the underlying baseline. Across corrupted image classification and continual semantic segmentation, STAG provides broadly applicable performance gains for strong TTA baselines on both CNN and Transformer architectures regardless of the underlying normalization scheme, with particularly large gains under challenging online regimes such as imbalanced label shifts, single-sample adaptation, mixed corruption streams and long-horizon continual TTA.

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。

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