Temporal-Consistent Video Restoration with Pre-trained Diffusion Models
Hengkang Wang, Yang Liu, Huidong Liu, Chien-Chih Wang, Yanhui Guo, Hongdong Li, Bryan Wang, Ju Sun
TL;DR
This work tackles video restoration with pre-trained image diffusion models by reformulating the problem as a Maximum a Posteriori (MAP) optimization in the seed space of diffusion models. By reparameterizing frames as X = D ∘ R(Z) and optimizing seeds Z, the authors avoid accumulation of diffusion-approximation errors and leverage strong LDM priors for VR. They introduce a bilevel temporal-consistency strategy: semantic-level consistency via a noise-prior clustering of seeds (Z = z_shared 1^T + R) and pixel-level consistency via progressive warping with optical-flow refinements (RAFT) and EMA-smoothed flows, plus an efficient optimization framework using DDIM with only 4 steps, a mean-value theorem reformulation, and low-rank residuals to reduce memory. Experiments across five VR tasks on DAVIS, REDS, SPMS, and UDM10 demonstrate substantial improvements in both visual quality (PSNR/SSIM/LPIPS) and temporal consistency (WE), with notable robustness to diverse degradations and better scalability than CG-based approaches.
Abstract
Video restoration (VR) aims to recover high-quality videos from degraded ones. Although recent zero-shot VR methods using pre-trained diffusion models (DMs) show good promise, they suffer from approximation errors during reverse diffusion and insufficient temporal consistency. Moreover, dealing with 3D video data, VR is inherently computationally intensive. In this paper, we advocate viewing the reverse process in DMs as a function and present a novel Maximum a Posterior (MAP) framework that directly parameterizes video frames in the seed space of DMs, eliminating approximation errors. We also introduce strategies to promote bilevel temporal consistency: semantic consistency by leveraging clustering structures in the seed space, and pixel-level consistency by progressive warping with optical flow refinements. Extensive experiments on multiple virtual reality tasks demonstrate superior visual quality and temporal consistency achieved by our method compared to the state-of-the-art.
