VISTA-Bench: Do Vision-Language Models Really Understand Visualized Text as Well as Pure Text?
Qing'an Liu, Juntong Feng, Yuhao Wang, Xinzhe Han, Yujie Cheng, Yue Zhu, Haiwen Diao, Yunzhi Zhuge, Huchuan Lu
TL;DR
VISTA-Bench addresses whether vision-language models can match pure-text understanding when language is rendered as visualized text. It presents a rigorously controlled, 1,500-sample benchmark with a LaTeX-based rendering pipeline and a VLM-based fidelity filter to compare VT and text inputs across perception, reasoning, and knowledge tasks. Across more than 20 VLMs, the study uncovers a pervasive modality gap that worsens with perceptual difficulty, suggesting that strong pure-text performance does not guarantee VT robustness. The results highlight perceptual robustness as the core bottleneck and advocate for unified, robust representations that bridge tokenized text and pixel-based language.
Abstract
Vision-Language Models (VLMs) have achieved impressive performance in cross-modal understanding across textual and visual inputs, yet existing benchmarks predominantly focus on pure-text queries. In real-world scenarios, language also frequently appears as visualized text embedded in images, raising the question of whether current VLMs handle such input requests comparably. We introduce VISTA-Bench, a systematic benchmark from multimodal perception, reasoning, to unimodal understanding domains. It evaluates visualized text understanding by contrasting pure-text and visualized-text questions under controlled rendering conditions. Extensive evaluation of over 20 representative VLMs reveals a pronounced modality gap: models that perform well on pure-text queries often degrade substantially when equivalent semantic content is presented as visualized text. This gap is further amplified by increased perceptual difficulty, highlighting sensitivity to rendering variations despite unchanged semantics. Overall, VISTA-Bench provides a principled evaluation framework to diagnose this limitation and to guide progress toward more unified language representations across tokenized text and pixels. The source dataset is available at https://github.com/QingAnLiu/VISTA-Bench.
