Vision as a Dialect: Unifying Visual Understanding and Generation via Text-Aligned Representations
This work addresses the challenge of integrating vision and text for AI systems, offering a unified approach that could benefit multimodal applications, though it appears incremental by building on existing tokenization and LLM techniques.
The paper tackles the problem of unifying visual understanding and generation by introducing a multimodal framework with a Text-Aligned Tokenizer (TA-Tok) that converts images into discrete tokens aligned with text, enabling cross-modal input and output without modality-specific designs. It shows that Tar matches or surpasses existing multimodal LLM methods, achieving faster convergence and greater training efficiency.
This paper presents a multimodal framework that attempts to unify visual understanding and generation within a shared discrete semantic representation. At its core is the Text-Aligned Tokenizer (TA-Tok), which converts images into discrete tokens using a text-aligned codebook projected from a large language model's (LLM) vocabulary. By integrating vision and text into a unified space with an expanded vocabulary, our multimodal LLM, Tar, enables cross-modal input and output through a shared interface, without the need for modality-specific designs. Additionally, we propose scale-adaptive encoding and decoding to balance efficiency and visual detail, along with a generative de-tokenizer to produce high-fidelity visual outputs. To address diverse decoding needs, we utilize two complementary de-tokenizers: a fast autoregressive model and a diffusion-based model. To enhance modality fusion, we investigate advanced pre-training tasks, demonstrating improvements in both visual understanding and generation. Experiments across benchmarks show that Tar matches or surpasses existing multimodal LLM methods, achieving faster convergence and greater training efficiency. Code, models, and data are available at https://tar.csuhan.com