VCP-CLIP: A visual context prompting model for zero-shot anomaly segmentation
Zhen Qu, Xian Tao, Mukesh Prasad, Fei Shen, Zhengtao Zhang, Xinyi Gong, Guiguang Ding
TL;DR
VCP-CLIP addresses zero-shot anomaly segmentation by introducing visual context prompting to CLIP. The Pre-VCP module injects global image context into text prompts, while the Post-VCP module leverages fine-grained image features to refine text embeddings via cross-modal attention, enabling robust anomaly localization on unseen products without product-specific prompts. Across 10 real industrial datasets, VCP-CLIP achieves state-of-the-art zero-shot performance, with strong improvements in AP and robust prompt generalization during testing. The approach reduces reliance on handcrafted prompts and demonstrates practical potential for privacy-preserving, data-efficient industrial defect inspection.
Abstract
Recently, large-scale vision-language models such as CLIP have demonstrated immense potential in zero-shot anomaly segmentation (ZSAS) task, utilizing a unified model to directly detect anomalies on any unseen product with painstakingly crafted text prompts. However, existing methods often assume that the product category to be inspected is known, thus setting product-specific text prompts, which is difficult to achieve in the data privacy scenarios. Moreover, even the same type of product exhibits significant differences due to specific components and variations in the production process, posing significant challenges to the design of text prompts. In this end, we propose a visual context prompting model (VCP-CLIP) for ZSAS task based on CLIP. The insight behind VCP-CLIP is to employ visual context prompting to activate CLIP's anomalous semantic perception ability. In specific, we first design a Pre-VCP module to embed global visual information into the text prompt, thus eliminating the necessity for product-specific prompts. Then, we propose a novel Post-VCP module, that adjusts the text embeddings utilizing the fine-grained features of the images. In extensive experiments conducted on 10 real-world industrial anomaly segmentation datasets, VCP-CLIP achieved state-of-the-art performance in ZSAS task. The code is available at https://github.com/xiaozhen228/VCP-CLIP.
