Accelerating Image Generation with Sub-path Linear Approximation Model
Chen Xu, Tianhui Song, Weixin Feng, Xubin Li, Tiezheng Ge, Bo Zheng, Limin Wang
TL;DR
SPLAM addresses the slow inference of diffusion models by modeling PF-ODE trajectories as sub-paths and learning through Sub-Path Linear (SL) ODEs to provide progressive, continuous error estimates. It decomposes the denoising objective into components that SL-ODEs can optimize with smaller cumulative errors and introduces SPLAD to distill these ideas into latent diffusion models, enabling efficient training. Empirical results on LAION and COCO show SPLAM achieving high-quality generation with 2–4 steps, outperforming existing acceleration methods in both FID and image quality while requiring only about 6 A100 GPU days. The approach combines a principled sub-path interpolation, gamma-conditioned training, and selective distillation to deliver practical, fast diffusion-based synthesis with strong generalization across backbones and datasets.
Abstract
Diffusion models have significantly advanced the state of the art in image, audio, and video generation tasks. However, their applications in practical scenarios are hindered by slow inference speed. Drawing inspiration from the approximation strategies utilized in consistency models, we propose the Sub-path Linear Approximation Model (SLAM), which accelerates diffusion models while maintaining high-quality image generation. SLAM treats the PF-ODE trajectory as a series of PF-ODE sub-paths divided by sampled points, and harnesses sub-path linear (SL) ODEs to form a progressive and continuous error estimation along each individual PF-ODE sub-path. The optimization on such SL-ODEs allows SLAM to construct denoising mappings with smaller cumulative approximated errors. An efficient distillation method is also developed to facilitate the incorporation of more advanced diffusion models, such as latent diffusion models. Our extensive experimental results demonstrate that SLAM achieves an efficient training regimen, requiring only 6 A100 GPU days to produce a high-quality generative model capable of 2 to 4-step generation with high performance. Comprehensive evaluations on LAION, MS COCO 2014, and MS COCO 2017 datasets also illustrate that SLAM surpasses existing acceleration methods in few-step generation tasks, achieving state-of-the-art performance both on FID and the quality of the generated images.
