Papers › UniPC: A Unified Predictor-Corrector Framework for Fast Sampling of Diffusion Models

UniPC: A Unified Predictor-Corrector Framework for Fast Sampling of Diffusion Models

9 Feb 2023NeurIPS 2023 11arXiv:2302.04867archive 2025-07-28

Wenliang Zhao, Lujia Bai, Yongming Rao, Jie zhou, Jiwen Lu

Diffusion probabilistic models (DPMs) have demonstrated a very promising ability in high-resolution image synthesis. However, sampling from a pre-trained DPM is time-consuming due to the multiple evaluations of the denoising network, making it more and more important to accelerate the sampling of DPMs. Despite recent progress in designing fast samplers, existing methods still cannot generate satisfying images in many applications where fewer steps (e.g., $<$10) are favored. In this paper, we develop a unified corrector (UniC) that can be applied after any existing DPM sampler to increase the order of accuracy without extra model evaluations, and derive a unified predictor (UniP) that supports arbitrary order as a byproduct. Combining UniP and UniC, we propose a unified predictor-corrector framework called UniPC for the fast sampling of DPMs, which has a unified analytical form for any order and can significantly improve the sampling quality over previous methods, especially in extremely few steps. We evaluate our methods through extensive experiments including both unconditional and conditional sampling using pixel-space and latent-space DPMs. Our UniPC can achieve 3.87 FID on CIFAR10 (unconditional) and 7.51 FID on ImageNet 256×256 (conditional) with only 10 function evaluations. Code is available at https://github.com/wl-zhao/UniPC.

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interpolate_fn wl-zhao/UniPC/example/score_sde_pytorch/uni_pc.py official repository ran · our draft was wrong fingerprinted MIT (permissive) · 39c68b6295eaca2f · report
interpolate_fn wl-zhao/unipc/example/score_sde_pytorch/uni_pc.py official repository ran · our draft was wrong fingerprinted MIT (permissive) · 6a35b62fbc80f70a · report
UniPC wl-zhao/unipc/uni_pc.py official repository ran MIT (permissive) · bbcc7bee81a99149 · report
expand_dims wl-zhao/unipc/example/score_sde_pytorch/uni_pc.py official repository ran · our draft was wrong MIT (permissive) · e6110366588c5c65 · report
model_wrapper wl-zhao/unipc/example/score_sde_pytorch/uni_pc.py official repository ran · our draft was wrong MIT (permissive) · 64098eb6704a58dd · report
model_wrapper wl-zhao/unipc/example/stable-diffusion/ldm/models/diffusion/uni_pc/uni_pc.py official repository ran · fixture could not drive it MIT (permissive) · 3552d38797b670d4 · report
expand_dims wl-zhao/UniPC/example/score_sde_pytorch/uni_pc.py official repository unverified MIT (permissive) · 292d0a3a80570d32 · report
model_wrapper wl-zhao/UniPC/example/score_sde_pytorch/uni_pc.py official repository unverified MIT (permissive) · 812cebe843fafdb2 · report

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