Scale Where It Matters: Training-Free Localized Scaling for Diffusion Models

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Ren, Qin, Wang, Yufei, Guo, Lanqing, Zhang, Wen, Fan, Zhiwen, You, Chenyu
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866917343779618816
author Ren, Qin
Wang, Yufei
Guo, Lanqing
Zhang, Wen
Fan, Zhiwen
You, Chenyu
author_facet Ren, Qin
Wang, Yufei
Guo, Lanqing
Zhang, Wen
Fan, Zhiwen
You, Chenyu
contents Diffusion models have become the dominant paradigm in text-to-image generation, and test-time scaling (TTS) improves sample quality by allocating additional computation at inference. Existing TTS methods, however, resample the entire image, while generation quality is often spatially heterogeneous. This leads to unnecessary computation on regions that are already correct, and localized defects remain insufficiently corrected. In this paper, we explore a new direction - Localized TTS - that adaptively resamples defective regions while preserving high-quality regions, thereby substantially reducing the search space. This raises two challenges: accurately localizing defects and maintaining global consistency. We propose LoTTS, the first fully training-free framework for localized TTS. For defect localization, LoTTS contrasts cross- and self-attention signals under quality-aware prompts (e.g., high-quality vs. low-quality) to identify defective regions, and then refines them into coherent masks. For consistency, LoTTS perturbs only defective regions and denoises them locally, ensuring that corrections remain confined while the rest of the image remains undisturbed. Extensive experiments on SD2.1, SDXL, and FLUX demonstrate that LoTTS achieves state-of-the-art performance: it consistently improves both local quality and global fidelity, while reducing GPU cost by 2-4x compared to Best-of-N sampling. These findings establish localized TTS as a promising new direction for scaling diffusion models at inference time.
format Preprint
id arxiv_https___arxiv_org_abs_2511_19917
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Scale Where It Matters: Training-Free Localized Scaling for Diffusion Models
Ren, Qin
Wang, Yufei
Guo, Lanqing
Zhang, Wen
Fan, Zhiwen
You, Chenyu
Computer Vision and Pattern Recognition
Diffusion models have become the dominant paradigm in text-to-image generation, and test-time scaling (TTS) improves sample quality by allocating additional computation at inference. Existing TTS methods, however, resample the entire image, while generation quality is often spatially heterogeneous. This leads to unnecessary computation on regions that are already correct, and localized defects remain insufficiently corrected. In this paper, we explore a new direction - Localized TTS - that adaptively resamples defective regions while preserving high-quality regions, thereby substantially reducing the search space. This raises two challenges: accurately localizing defects and maintaining global consistency. We propose LoTTS, the first fully training-free framework for localized TTS. For defect localization, LoTTS contrasts cross- and self-attention signals under quality-aware prompts (e.g., high-quality vs. low-quality) to identify defective regions, and then refines them into coherent masks. For consistency, LoTTS perturbs only defective regions and denoises them locally, ensuring that corrections remain confined while the rest of the image remains undisturbed. Extensive experiments on SD2.1, SDXL, and FLUX demonstrate that LoTTS achieves state-of-the-art performance: it consistently improves both local quality and global fidelity, while reducing GPU cost by 2-4x compared to Best-of-N sampling. These findings establish localized TTS as a promising new direction for scaling diffusion models at inference time.
title Scale Where It Matters: Training-Free Localized Scaling for Diffusion Models
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2511.19917