Multilingual Pretraining for Pixel Language Models

Ilker Kesen, Jonas F. Lotz, Ingo Ziegler, Phillip Rust, Desmond Elliott


Abstract
Pixel language models operate directly on images of rendered text, eliminating the need for a fixed vocabulary. While these models have demonstrated strong capabilities for downstream cross-lingual transfer, multilingual pretraining remains underexplored. We introduce PIXEL-M4, a model pretrained on four visually and linguistically diverse languages: English, Hindi, Ukrainian, and Simplified Chinese. Multilingual evaluations on semantic and syntactic tasks show that PIXEL-M4 outperforms an English-only counterpart on non-Latin scripts. Word-level probing analyses confirm that PIXEL-M4 captures rich linguistic features, even in languages not seen during pretraining. Furthermore, an analysis of its hidden representations shows that multilingual pretraining yields a semantic embedding space closely aligned across the languages used for pretraining. This work demonstrates that multilingual pretraining substantially enhances the capability of pixel language models to effectively support a diverse set of languages.
Anthology ID:
2025.emnlp-main.1504
Volume:
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2025
Address:
Suzhou, China
Editors:
Christos Christodoulopoulos, Tanmoy Chakraborty, Carolyn Rose, Violet Peng
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
29582–29599
Language:
URL:
https://preview.aclanthology.org/ingest-emnlp/2025.emnlp-main.1504/
DOI:
Bibkey:
Cite (ACL):
Ilker Kesen, Jonas F. Lotz, Ingo Ziegler, Phillip Rust, and Desmond Elliott. 2025. Multilingual Pretraining for Pixel Language Models. In Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing, pages 29582–29599, Suzhou, China. Association for Computational Linguistics.
Cite (Informal):
Multilingual Pretraining for Pixel Language Models (Kesen et al., EMNLP 2025)
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https://preview.aclanthology.org/ingest-emnlp/2025.emnlp-main.1504.pdf
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