Cross-modal Proxy Evolving for OOD Detection with Vision-Language Models

Fuente: arXiv
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Autori principali: Tang, Hao, Liu, Yu, Yan, Shuanglin, Shen, Fei, He, Shengfeng, Qin, Jing
Natura: Preprint
Pubblicazione: 2026
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author Tang, Hao
Liu, Yu
Yan, Shuanglin
Shen, Fei
He, Shengfeng
Qin, Jing
author_facet Tang, Hao
Liu, Yu
Yan, Shuanglin
Shen, Fei
He, Shengfeng
Qin, Jing
contents Reliable zero-shot detection of out-of-distribution (OOD) inputs is critical for deploying vision-language models in open-world settings. However, the lack of labeled negatives in zero-shot OOD detection necessitates proxy signals that remain effective under distribution shift. Existing negative-label methods rely on a fixed set of textual proxies, which (i) sparsely sample the semantic space beyond in-distribution (ID) classes and (ii) remain static while only visual features drift, leading to cross-modal misalignment and unstable predictions. In this paper, we propose CoEvo, a training- and annotation-free test-time framework that performs bidirectional, sample-conditioned adaptation of both textual and visual proxies. Specifically, CoEvo introduces a proxy-aligned co-evolution mechanism to maintain two evolving proxy caches, which dynamically mines contextual textual negatives guided by test images and iteratively refines visual proxies, progressively realigning cross-modal similarities and enlarging local OOD margins. Finally, we dynamically re-weight the contributions of dual-modal proxies to obtain a calibrated OOD score that is robust to distribution shift. Extensive experiments on standard benchmarks demonstrate that CoEvo achieves state-of-the-art performance, improving AUROC by 1.33% and reducing FPR95 by 45.98% on ImageNet-1K compared to strong negative-label baselines.
format Preprint
id arxiv_https___arxiv_org_abs_2601_08476
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Cross-modal Proxy Evolving for OOD Detection with Vision-Language Models
Tang, Hao
Liu, Yu
Yan, Shuanglin
Shen, Fei
He, Shengfeng
Qin, Jing
Computer Vision and Pattern Recognition
Multimedia
Reliable zero-shot detection of out-of-distribution (OOD) inputs is critical for deploying vision-language models in open-world settings. However, the lack of labeled negatives in zero-shot OOD detection necessitates proxy signals that remain effective under distribution shift. Existing negative-label methods rely on a fixed set of textual proxies, which (i) sparsely sample the semantic space beyond in-distribution (ID) classes and (ii) remain static while only visual features drift, leading to cross-modal misalignment and unstable predictions. In this paper, we propose CoEvo, a training- and annotation-free test-time framework that performs bidirectional, sample-conditioned adaptation of both textual and visual proxies. Specifically, CoEvo introduces a proxy-aligned co-evolution mechanism to maintain two evolving proxy caches, which dynamically mines contextual textual negatives guided by test images and iteratively refines visual proxies, progressively realigning cross-modal similarities and enlarging local OOD margins. Finally, we dynamically re-weight the contributions of dual-modal proxies to obtain a calibrated OOD score that is robust to distribution shift. Extensive experiments on standard benchmarks demonstrate that CoEvo achieves state-of-the-art performance, improving AUROC by 1.33% and reducing FPR95 by 45.98% on ImageNet-1K compared to strong negative-label baselines.
title Cross-modal Proxy Evolving for OOD Detection with Vision-Language Models
topic Computer Vision and Pattern Recognition
Multimedia
url https://arxiv.org/abs/2601.08476