PromptEnhancer: A Simple Approach to Enhance Text-to-Image Models via Chain-of-Thought Prompt Rewriting

Fuente: arXiv
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Main Authors: Wang, Linqing, Xing, Ximing, Cheng, Yiji, Zhao, Zhiyuan, Li, Donghao, Hang, Tiankai, Tao, Jiale, Wang, Qixun, Li, Ruihuang, Chen, Comi, Li, Xin, Wu, Mingrui, Deng, Xinchi, Gu, Shuyang, Wang, Chunyu, Lu, Qinglin
Format: Preprint
Published: 2025
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author Wang, Linqing
Xing, Ximing
Cheng, Yiji
Zhao, Zhiyuan
Li, Donghao
Hang, Tiankai
Tao, Jiale
Wang, Qixun
Li, Ruihuang
Chen, Comi
Li, Xin
Wu, Mingrui
Deng, Xinchi
Gu, Shuyang
Wang, Chunyu
Lu, Qinglin
author_facet Wang, Linqing
Xing, Ximing
Cheng, Yiji
Zhao, Zhiyuan
Li, Donghao
Hang, Tiankai
Tao, Jiale
Wang, Qixun
Li, Ruihuang
Chen, Comi
Li, Xin
Wu, Mingrui
Deng, Xinchi
Gu, Shuyang
Wang, Chunyu
Lu, Qinglin
contents Recent advancements in text-to-image (T2I) diffusion models have demonstrated remarkable capabilities in generating high-fidelity images. However, these models often struggle to faithfully render complex user prompts, particularly in aspects like attribute binding, negation, and compositional relationships. This leads to a significant mismatch between user intent and the generated output. To address this challenge, we introduce PromptEnhancer, a novel and universal prompt rewriting framework that enhances any pretrained T2I model without requiring modifications to its weights. Unlike prior methods that rely on model-specific fine-tuning or implicit reward signals like image-reward scores, our framework decouples the rewriter from the generator. We achieve this by training a Chain-of-Thought (CoT) rewriter through reinforcement learning, guided by a dedicated reward model we term the AlignEvaluator. The AlignEvaluator is trained to provide explicit and fine-grained feedback based on a systematic taxonomy of 24 key points, which are derived from a comprehensive analysis of common T2I failure modes. By optimizing the CoT rewriter to maximize the reward from our AlignEvaluator, our framework learns to generate prompts that are more precisely interpreted by T2I models. Extensive experiments on the HunyuanImage 2.1 model demonstrate that PromptEnhancer significantly improves image-text alignment across a wide range of semantic and compositional challenges. Furthermore, we introduce a new, high-quality human preference benchmark to facilitate future research in this direction.
format Preprint
id arxiv_https___arxiv_org_abs_2509_04545
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle PromptEnhancer: A Simple Approach to Enhance Text-to-Image Models via Chain-of-Thought Prompt Rewriting
Wang, Linqing
Xing, Ximing
Cheng, Yiji
Zhao, Zhiyuan
Li, Donghao
Hang, Tiankai
Tao, Jiale
Wang, Qixun
Li, Ruihuang
Chen, Comi
Li, Xin
Wu, Mingrui
Deng, Xinchi
Gu, Shuyang
Wang, Chunyu
Lu, Qinglin
Computer Vision and Pattern Recognition
Recent advancements in text-to-image (T2I) diffusion models have demonstrated remarkable capabilities in generating high-fidelity images. However, these models often struggle to faithfully render complex user prompts, particularly in aspects like attribute binding, negation, and compositional relationships. This leads to a significant mismatch between user intent and the generated output. To address this challenge, we introduce PromptEnhancer, a novel and universal prompt rewriting framework that enhances any pretrained T2I model without requiring modifications to its weights. Unlike prior methods that rely on model-specific fine-tuning or implicit reward signals like image-reward scores, our framework decouples the rewriter from the generator. We achieve this by training a Chain-of-Thought (CoT) rewriter through reinforcement learning, guided by a dedicated reward model we term the AlignEvaluator. The AlignEvaluator is trained to provide explicit and fine-grained feedback based on a systematic taxonomy of 24 key points, which are derived from a comprehensive analysis of common T2I failure modes. By optimizing the CoT rewriter to maximize the reward from our AlignEvaluator, our framework learns to generate prompts that are more precisely interpreted by T2I models. Extensive experiments on the HunyuanImage 2.1 model demonstrate that PromptEnhancer significantly improves image-text alignment across a wide range of semantic and compositional challenges. Furthermore, we introduce a new, high-quality human preference benchmark to facilitate future research in this direction.
title PromptEnhancer: A Simple Approach to Enhance Text-to-Image Models via Chain-of-Thought Prompt Rewriting
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2509.04545