GLOBE: Training-Free Calibration for Image-Text Retrieval with Global-Local Bias and Graph Evidence

Xuzhe Zhao, Zhirun Yue, Xingyue Xu, Houde Liu, Kaichen Dong


Abstract
Multimodal contrastive models are widely used for bidirectional image-text retrieval, but their rankings remain vulnerable to attraction bias, where certain candidates become hubs for many unrelated queries. Existing training-free normalization methods suppress such hubs, but may also penalize candidates that are genuinely relevant. We propose GLOBE, a training-free plug-in module that combines global-local bias calibration with graph-based semantic evidence to suppress unsupported hubs while preserving true matches. Across MS-COCO and Flickr30K, GLOBE improves diverse frozen retrieval backbones, achieving up to 7.9% absolute Recall@1 gain over the original model and up to 5.2% over strong training-free baselines. We further construct IRB-COCO-500, a mixed real-and-synthetic benchmark with AI-generated near-positive distractors, and show that GLOBE improves retrieval robustness in this challenging setting.
Anthology ID:
2026.emnlp-main.1985
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
45154–45173
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1985/
DOI:
Bibkey:
Cite (ACL):
Xuzhe Zhao, Zhirun Yue, Xingyue Xu, Houde Liu, and Kaichen Dong. 2026. GLOBE: Training-Free Calibration for Image-Text Retrieval with Global-Local Bias and Graph Evidence. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 45154–45173, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
GLOBE: Training-Free Calibration for Image-Text Retrieval with Global-Local Bias and Graph Evidence (Zhao et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1985.pdf