Ckt: cross-image knowledge transfer for texture anomaly detection

Most anomaly detection models are often sensitive to unavoidable disturbance or non-defective "visual defects", and such near abnormal samples are easily identified as anomalies, resulting in a high false detection rate. To this end, we propose a novel multi-scale Cross-image Knowledge Transfer anomaly detection model, namely CKT. Different from most existing intra-image distillation methods, our model transfers both the intra-image knowledge of the normal image and the inter-image knowledge of the normal image and the near-anomaly prototype, to assist the model to learn more robust normal patterns. Furthermore, we develop a cross-image attention module for explicitly enhancing the near-abnormal pattern learning during the distillation procedure, to alleviate the problem of high false detection rate induced by near-abnormal instances. Extensive experiments on texture datasets, such as KSDD2, MT, AITEX, and the textural subset of Mvtec-AD, show that the proposed CKT model can outperform most of the current unsupervised anomaly detection methods. Compared with the existing distillation based anomaly detection frameworks, our work can get significant gains with a margin of 2%.