Density-Aware Translation of Spurious Correlations in Zero-Shot VLMs

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Hasanebrahimi, Afsaneh, Huang, Hanxun, Leckie, Christopher, Erfani, Sarah
Natura: Preprint
Pubblicazione: 2026
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866913178080772096
author Hasanebrahimi, Afsaneh
Huang, Hanxun
Leckie, Christopher
Erfani, Sarah
author_facet Hasanebrahimi, Afsaneh
Huang, Hanxun
Leckie, Christopher
Erfani, Sarah
contents Vision-Language models (VLMs), such as CLIP, achieve powerful zero-shot classification. However, their predictions remain sensitive to spurious correlations, where contextual cues dominate over semantic content. Earlier solutions typically rely on fine-tuning or prompt engineering, which either undermine the advantages of pre-trained models or are prone to hallucination. In this work, we propose Density-Aware Translation (DAT) that refines image-text similarity scores using a local geometric density term derived from group reference sets. Our approach is motivated by the phenomenon that CLIP embeddings exhibit a modality gap and lie on an anisotropic shell in the feature space: common patterns cluster near the mean, while rare patterns are pushed outward. This geometry creates uneven alignment, where spurious correlations are amplified while semantically meaningful but rare cues are marginalised. To address this, we employ a relative measure to rescale similarities based on embedding density, suppressing overconfident scores in diffuse regions while preserving dense, semantically consistent matches. Experimental results on benchmark datasets demonstrate consistent improvements in worst-group and average accuracy, highlighting density-aware translation as a simple and effective calibration mechanism for reliable zero-shot classification using multimodal models.
format Preprint
id arxiv_https___arxiv_org_abs_2606_01710
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Density-Aware Translation of Spurious Correlations in Zero-Shot VLMs
Hasanebrahimi, Afsaneh
Huang, Hanxun
Leckie, Christopher
Erfani, Sarah
Computer Vision and Pattern Recognition
Machine Learning
Vision-Language models (VLMs), such as CLIP, achieve powerful zero-shot classification. However, their predictions remain sensitive to spurious correlations, where contextual cues dominate over semantic content. Earlier solutions typically rely on fine-tuning or prompt engineering, which either undermine the advantages of pre-trained models or are prone to hallucination. In this work, we propose Density-Aware Translation (DAT) that refines image-text similarity scores using a local geometric density term derived from group reference sets. Our approach is motivated by the phenomenon that CLIP embeddings exhibit a modality gap and lie on an anisotropic shell in the feature space: common patterns cluster near the mean, while rare patterns are pushed outward. This geometry creates uneven alignment, where spurious correlations are amplified while semantically meaningful but rare cues are marginalised. To address this, we employ a relative measure to rescale similarities based on embedding density, suppressing overconfident scores in diffuse regions while preserving dense, semantically consistent matches. Experimental results on benchmark datasets demonstrate consistent improvements in worst-group and average accuracy, highlighting density-aware translation as a simple and effective calibration mechanism for reliable zero-shot classification using multimodal models.
title Density-Aware Translation of Spurious Correlations in Zero-Shot VLMs
topic Computer Vision and Pattern Recognition
Machine Learning
url https://arxiv.org/abs/2606.01710