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arXiv 2602.00522cs.CV

MRAD: 无监督异常检测中的记忆驱动检索

MRAD: Zero-Shot Anomaly Detection with Memory-Driven Retrieval

Institute of Automation, Chinese Academy of Sciences(中国科学院自动化研究所);School of Artificial Intelligence, University of Chinese Academy of Sciences(中国科学院大学人工智能学院)

Chaoran Xu, Chengkan Lv, Qiyu Chen, Feng Zhang, Zhengtao Zhang

AI总结:

MRAD通过记忆驱动检索实现无监督异常检测,利用记忆库提升异常分类和分割性能。

摘要:

无监督异常检测(ZSAD)通常依赖于预训练的视觉或视觉-语言模型,但许多现有方法使用提示学习或复杂的建模来拟合数据分布,导致训练或推理成本高且跨域稳定性有限。为了解决这些限制,我们提出了记忆检索异常检测方法(MRAD),一个统一的框架,用直接的记忆检索取代参数拟合。免训练基础模型MRAD-TF冻结了CLIP图像编码器,并从辅助数据中构建了两级记忆库(图像级和像素级),其中特征-标签对被显式存储为键和值。在推理过程中,通过记忆库的相似性检索直接获得异常评分。基于MRAD-TF,我们进一步提出了两个轻量级变体作为增强:(i)MRAD-FT通过两个线性层微调检索度量,以增强正常与异常之间的区分度;(ii)MRAD-CLIP将MRAD-FT中的正常和异常区域先验注入到CLIP的可学习文本提示中,加强了对未见类别的泛化能力。在16个工业和医疗数据集中,MRAD框架在无训练和训练基础上均显示出在异常分类和分割上的优越性能。我们的工作表明,充分利用原始数据的经验分布,而不是仅依赖模型拟合,可以实现更强的异常检测性能。代码将在https://github.com/CROVO1026/MRAD上公开发布。

英文摘要:

Zero-shot anomaly detection (ZSAD) often leverages pretrained vision or vision-language models, but many existing methods use prompt learning or complex modeling to fit the data distribution, resulting in high training or inference cost and limited cross-domain stability. To address these limitations, we propose Memory-Retrieval Anomaly Detection method (MRAD), a unified framework that replaces parametric fitting with a direct memory retrieval. The train-free base model, MRAD-TF, freezes the CLIP image encoder and constructs a two-level memory bank (image-level and pixel-level) from auxiliary data, where feature-label pairs are explicitly stored as keys and values. During inference, anomaly scores are obtained directly by similarity retrieval over the memory bank. Based on the MRAD-TF, we further propose two lightweight variants as enhancements: (i) MRAD-FT fine-tunes the retrieval metric with two linear layers to enhance the discriminability between normal and anomaly; (ii) MRAD-CLIP injects the normal and anomalous region priors from the MRAD-FT as dynamic biases into CLIP's learnable text prompts, strengthening generalization to unseen categories. Across 16 industrial and medical datasets, the MRAD framework consistently demonstrates superior performance in anomaly classification and segmentation, under both train-free and training-based settings. Our work shows that fully leveraging the empirical distribution of raw data, rather than relying only on model fitting, can achieve stronger anomaly detection performance. The code will be publicly released at https://github.com/CROVO1026/MRAD.

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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