Dual-Modality Anchor-Guided Filtering for Test-time Prompt Tuning

Fuente: arXiv
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Main Authors: Choi, Jungwon, Kim, Eunwoo
Format: Preprint
Published: 2026
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author Choi, Jungwon
Kim, Eunwoo
author_facet Choi, Jungwon
Kim, Eunwoo
contents Test-Time Prompt Tuning (TPT) adapts vision-language models using augmented views, but its effectiveness is hindered by the challenge of determining which views are beneficial. Standard entropy-based filtering relies on the internal confidence scores of the model, which are often miscalibrated under distribution shift, assigning high confidence to irrelevant crops or background regions while ignoring semantic content. To address this, we propose a dual-modality anchor-guided framework that grounds view selection in semantic evidence. We introduce a text anchor from attribute-rich descriptions, to provide fine-grained class semantics, and an adaptive image anchor that captures evolving test-time statistics. Using these anchors, we filter views based on alignment and confidence, ensuring that only informative views guide adaptation. Moreover, we treat the anchors as auxiliary predictive heads and combine their predictions with the original output in a confidence-weighted ensemble, yielding a stable supervision signal for prompt updates. Extensive experiments on 15 benchmark datasets demonstrate new state-of-the-art performance, highlighting the contribution of anchor-guided supervision as a foundation for robust prompt updates.
format Preprint
id arxiv_https___arxiv_org_abs_2604_12403
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Dual-Modality Anchor-Guided Filtering for Test-time Prompt Tuning
Choi, Jungwon
Kim, Eunwoo
Computer Vision and Pattern Recognition
Test-Time Prompt Tuning (TPT) adapts vision-language models using augmented views, but its effectiveness is hindered by the challenge of determining which views are beneficial. Standard entropy-based filtering relies on the internal confidence scores of the model, which are often miscalibrated under distribution shift, assigning high confidence to irrelevant crops or background regions while ignoring semantic content. To address this, we propose a dual-modality anchor-guided framework that grounds view selection in semantic evidence. We introduce a text anchor from attribute-rich descriptions, to provide fine-grained class semantics, and an adaptive image anchor that captures evolving test-time statistics. Using these anchors, we filter views based on alignment and confidence, ensuring that only informative views guide adaptation. Moreover, we treat the anchors as auxiliary predictive heads and combine their predictions with the original output in a confidence-weighted ensemble, yielding a stable supervision signal for prompt updates. Extensive experiments on 15 benchmark datasets demonstrate new state-of-the-art performance, highlighting the contribution of anchor-guided supervision as a foundation for robust prompt updates.
title Dual-Modality Anchor-Guided Filtering for Test-time Prompt Tuning
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2604.12403