Towards Accurate Unified Anomaly Segmentation

Wenxin Ma, Qingsong Yao, Xiang Zhang, Zhelong Huang, Zihang Jiang, S.Kevin Zhou; Proceedings of the Winter Conference on Applications of Computer Vision (WACV), 2025, pp. 1342-1352

Unsupervised anomaly detection (UAD) from images strives to model normal data distributions creating discriminative representations to distinguish and precisely localize anomalies. Despite recent advancements in the efficient and unified one-for-all scheme challenges persist in accurately segmenting anomalies for further monitoring. Moreover this problem is obscured by the widely-used AUROC metric under imbalanced UAD settings. This motivates us to emphasize the significance of precise segmentation of anomaly pixels using pAP and DSC as metrics. To address the unsolved segmentation task we introduce the Unified Anomaly Segmentation (UniAS). UniAS presents a multi-level hybrid pipeline that progressively enhances normal information from coarse to fine incorporating a novel multi-granularity gated CNN (MGG-CNN) into Transformer layers to explicitly aggregate local details from different granularities. UniAS achieves state-of-the-art anomaly segmentation performance attaining 65.12/59.33 and 40.06/32.50 in pAP/DSC on the MVTec-AD and VisA datasets respectively surpassing previous methods significantly. The codes are shared at https://github.com/Mwxinnn/UniAS.