Exploring Position Encoding in Diffusion U-Net for Training-free High-resolution Image Generation

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Zhou, Feng, Cao, Pu, Ma, Yiyang, Yang, Lu, Yin, Jianqin
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866916651374477312
author Zhou, Feng
Cao, Pu
Ma, Yiyang
Yang, Lu
Yin, Jianqin
author_facet Zhou, Feng
Cao, Pu
Ma, Yiyang
Yang, Lu
Yin, Jianqin
contents Denoising higher-resolution latents via a pre-trained U-Net leads to repetitive and disordered image patterns. Although recent studies make efforts to improve generative quality by aligning denoising process across original and higher resolutions, the root cause of suboptimal generation is still lacking exploration. Through comprehensive analysis of position encoding in U-Net, we attribute it to inconsistent position encoding, sourced by the inadequate propagation of position information from zero-padding to latent features in convolution layers as resolution increases. To address this issue, we propose a novel training-free approach, introducing a Progressive Boundary Complement (PBC) method. This method creates dynamic virtual image boundaries inside the feature map to enhance position information propagation, enabling high-quality and rich-content high-resolution image synthesis. Extensive experiments demonstrate the superiority of our method.
format Preprint
id arxiv_https___arxiv_org_abs_2503_09830
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Exploring Position Encoding in Diffusion U-Net for Training-free High-resolution Image Generation
Zhou, Feng
Cao, Pu
Ma, Yiyang
Yang, Lu
Yin, Jianqin
Computer Vision and Pattern Recognition
Denoising higher-resolution latents via a pre-trained U-Net leads to repetitive and disordered image patterns. Although recent studies make efforts to improve generative quality by aligning denoising process across original and higher resolutions, the root cause of suboptimal generation is still lacking exploration. Through comprehensive analysis of position encoding in U-Net, we attribute it to inconsistent position encoding, sourced by the inadequate propagation of position information from zero-padding to latent features in convolution layers as resolution increases. To address this issue, we propose a novel training-free approach, introducing a Progressive Boundary Complement (PBC) method. This method creates dynamic virtual image boundaries inside the feature map to enhance position information propagation, enabling high-quality and rich-content high-resolution image synthesis. Extensive experiments demonstrate the superiority of our method.
title Exploring Position Encoding in Diffusion U-Net for Training-free High-resolution Image Generation
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2503.09830