One Token, Two Fates: A Unified Framework via Vision Token Manipulation Against MLLMs Hallucination

Fuente: arXiv
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Main Authors: Fa, Zhan, Duan, Yue, Zhang, Jian, Qi, Lei, Shi, Yinghuan
Format: Preprint
Published: 2026
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author Fa, Zhan
Duan, Yue
Zhang, Jian
Qi, Lei
Shi, Yinghuan
author_facet Fa, Zhan
Duan, Yue
Zhang, Jian
Qi, Lei
Shi, Yinghuan
contents Current training-free methods tackle MLLM hallucination with separate strategies: either enhancing visual signals or suppressing text inertia. However, these separate methods are insufficient due to critical trade-offs: simply enhancing vision often fails against strong language prior, while suppressing language can introduce extra image-irrelevant noise. Moreover, we find their naive combination is also ineffective, necessitating a unified framework. We propose such a framework by focusing on the core asset: the vision token. Our design leverages two key insights: (1) augmented images offer complementary visual semantics, and (2) removing vision tokens (information-gap) isolates hallucination tendencies more precisely than distorting images (modality-gap). Based on these, our framework uses vision tokens in two distinct ways, both operating on latent representations: our Synergistic Visual Calibration (SVC) module incorporates augmented tokens to strengthen visual representations, while our Causal Representation Calibration (CRC) module uses pruned tokens to create latent-space negative samples for correcting internal model biases. By harmonizing these two roles, our framework effectively restores the vision-language balance, significantly reducing object hallucinations, improving POPE accuracy by an average of 2% absolute on LLaVA-1.5 across multiple benchmarks with only a 1.06x inference latency overhead.
format Preprint
id arxiv_https___arxiv_org_abs_2603_10360
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle One Token, Two Fates: A Unified Framework via Vision Token Manipulation Against MLLMs Hallucination
Fa, Zhan
Duan, Yue
Zhang, Jian
Qi, Lei
Shi, Yinghuan
Computer Vision and Pattern Recognition
Current training-free methods tackle MLLM hallucination with separate strategies: either enhancing visual signals or suppressing text inertia. However, these separate methods are insufficient due to critical trade-offs: simply enhancing vision often fails against strong language prior, while suppressing language can introduce extra image-irrelevant noise. Moreover, we find their naive combination is also ineffective, necessitating a unified framework. We propose such a framework by focusing on the core asset: the vision token. Our design leverages two key insights: (1) augmented images offer complementary visual semantics, and (2) removing vision tokens (information-gap) isolates hallucination tendencies more precisely than distorting images (modality-gap). Based on these, our framework uses vision tokens in two distinct ways, both operating on latent representations: our Synergistic Visual Calibration (SVC) module incorporates augmented tokens to strengthen visual representations, while our Causal Representation Calibration (CRC) module uses pruned tokens to create latent-space negative samples for correcting internal model biases. By harmonizing these two roles, our framework effectively restores the vision-language balance, significantly reducing object hallucinations, improving POPE accuracy by an average of 2% absolute on LLaVA-1.5 across multiple benchmarks with only a 1.06x inference latency overhead.
title One Token, Two Fates: A Unified Framework via Vision Token Manipulation Against MLLMs Hallucination
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2603.10360