arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2403.07366cs.CVcs.LG

熵不足以支撑测试时自适应:从解耦因子的视角出发

Entropy is not Enough for Test-Time Adaptation: From the Perspective of Disentangled Factors

Seoul National University(首尔大学);Soongsil University(崇实大学);Yonsei University(延世大学)

Jonghyun Lee, Dahuin Jung, Saehyung Lee, Junsung Park, Juhyeon Shin, Uiwon Hwang, Sungroh Yoon

AI总结:

该研究指出熵作为测试时自适应(TTA)的置信度指标在有偏场景下不可靠,根源是忽略数据潜在解耦因子的影响,提出结合熵与新指标PLPD的DeYO方法,优先选择形状主导预测的样本,在多场景下性能优于基线。

摘要:

测试时自适应(Test-Time Adaptation, TTA)针对未见过的测试数据微调预训练深度神经网络。TTA的主要挑战在于在线更新期间无法访问完整测试数据集,这会导致误差累积。为缓解该问题,现有TTA方法将模型输出的熵用作置信度指标,旨在判定哪些样本引发误差的可能性更低。然而,通过实验研究我们观察到,在有偏场景下,熵作为TTA的置信度指标并不可靠;我们还从理论上揭示,这一问题的根源在于忽略了数据的潜在解耦因子对预测结果的影响。基于这些发现,我们提出了一种名为Destroy Your Object(DeYO)的新型TTA方法,该方法采用了我们新提出的置信度指标——伪标签概率差(Pseudo-Label Probability Difference, PLPD)。PLPD通过测量施加对象破坏变换前后的预测结果差异,量化对象形状对预测的影响。DeYO包含样本选择和样本加权两个模块,同时结合使用熵和PLPD。为实现鲁棒自适应,DeYO会优先选择预测时主要依赖形状信息的样本。我们的大量实验表明,在包括有偏场景和真实野外场景在内的多种场景下,DeYO的性能始终优于基线方法。项目页面公开于https://whitesnowdrop.github.io/DeYO/。

英文摘要:

Test-time adaptation (TTA) fine-tunes pre-trained deep neural networks for unseen test data. The primary challenge of TTA is limited access to the entire test dataset during online updates, causing error accumulation. To mitigate it, TTA methods have utilized the model output's entropy as a confidence metric that aims to determine which samples have a lower likelihood of causing error. Through experimental studies, however, we observed the unreliability of entropy as a confidence metric for TTA under biased scenarios and theoretically revealed that it stems from the neglect of the influence of latent disentangled factors of data on predictions. Building upon these findings, we introduce a novel TTA method named Destroy Your Object (DeYO), which leverages a newly proposed confidence metric named Pseudo-Label Probability Difference (PLPD). PLPD quantifies the influence of the shape of an object on prediction by measuring the difference between predictions before and after applying an object-destructive transformation. DeYO consists of sample selection and sample weighting, which employ entropy and PLPD concurrently. For robust adaptation, DeYO prioritizes samples that dominantly incorporate shape information when making predictions. Our extensive experiments demonstrate the consistent superiority of DeYO over baseline methods across various scenarios, including biased and wild. Project page is publicly available at https://whitesnowdrop.github.io/DeYO/.

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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