Test-time Prompt Refinement for Text-to-Image Models

Abstract:Text-to-image (T2I) generation models have made significant strides but still struggle with prompt sensitivity: even minor changes in prompt wording can yield inconsistent or inaccurate outputs. To address this challenge, we introduce a closed-loop, test-time prompt refinement framework that requires no additional training of the underlying T2I model, termed TIR. In our approach, each generation step is followed by a refinement step, where a pretrained multimodal large language model (MLLM) analyzes the output image and the user's prompt. The MLLM detects misalignments (e.g., missing objects, incorrect attributes) and produces a refined and physically grounded prompt for the next round of image generation. By iteratively refining the prompt and verifying alignment between the prompt and the image, TIR corrects errors, mirroring the iterative refinement process of human artists. We demonstrate that this closed-loop strategy improves alignment and visual coherence across multiple benchmark datasets, all while maintaining plug-and-play integration with black-box T2I models. Code is available at this https URL.

Accepted to ICCV 2025, MARS2 Workshop. Total 14 pages, 12 figures and 3 tables

Machine Learning (cs.LG)

arXiv:2507.22076 [cs.LG]

(or arXiv:2507.22076v2 [cs.LG] for this version)

https://doi.org/10.48550/arXiv.2507.22076 Focus to learn more arXiv-issued DOI via DataCite

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