FocusDiff: Advancing Fine-Grained Text-Image Alignment for Autoregressive Visual Generation through RL
Kaihang Pan, Wendong Bu, Yuruo Wu, Yang Wu, Kai Shen, Yunfei Li, Hang Zhao, Juncheng Li, Siliang Tang, Yueting Zhuang
TL;DR
The paper addresses the challenge of fine-grained text-image alignment in autoregressive text-to-image generation by introducing the PairComp benchmark, which tests models on paired prompts with subtle semantic differences. It proposes FocusDiff, comprising FocusDiff-Data and Pair-GRPO, to learn from differences between similar text-image pairs via a QA-based reward and an expanded group policy that balances exploration and exploitation. The approach yields state-of-the-art results on existing text-to-image benchmarks and substantial gains on PairComp, demonstrating improved control over visual tokens and robustness to counterfactual prompts. This work advances precise multimodal alignment in AR-based generation and offers a scalable framework for training data and RL-based refinement.
Abstract
Recent studies extend the autoregression paradigm to text-to-image generation, achieving performance comparable to diffusion models. However, our new PairComp benchmark -- featuring test cases of paired prompts with similar syntax but different fine-grained semantics -- reveals that existing models struggle with fine-grained text-image alignment thus failing to realize precise control over visual tokens. To address this, we propose FocusDiff, which enhances fine-grained text-image semantic alignment by focusing on subtle differences between similar text-image pairs. We construct a new dataset of paired texts and images with similar overall expressions but distinct local semantics, further introducing a novel reinforcement learning algorithm to emphasize such fine-grained semantic differences for desired image generation. Our approach achieves state-of-the-art performance on existing text-to-image benchmarks and significantly outperforms prior methods on PairComp.
