OSDEnhancer: Taming Real-World Space-Time Video Super-Resolution with One-Step Diffusion
Shuoyan Wei, Feng Li, Chen Zhou, Runmin Cong, Yao Zhao, Huihui Bai
TL;DR
OSDEnhancer tackles real-world STVSR by casting it as a one-step diffusion problem built on a pretrained diffusion backbone. It introduces a temporal-refinement and spatial-enhancement mixture-of-experts (TR-SE MoE) to separately learn temporal coherence and spatial detail, aided by a bidirectional deformable VAE decoder for robust cross-frame reconstruction. Starting from a linearly pre-interpolated latent, it achieves high-fidelity HR/HFR outputs with strong temporal consistency and robustness to complex degradations, while offering substantial efficiency gains over multi-step diffusion approaches. Empirical results on synthetic and real-world datasets show state-of-the-art performance across fidelity and perceptual metrics, with practical inference speedups (e.g., ~7x over certain diffusion-based STVSR baselines) enabling high-resolution video synthesis like a 97-frame $1024\times1024$ clip.
Abstract
Diffusion models (DMs) have demonstrated exceptional success in video super-resolution (VSR), showcasing a powerful capacity for generating fine-grained details. However, their potential for space-time video super-resolution (STVSR), which necessitates not only recovering realistic visual content from low-resolution to high-resolution but also improving the frame rate with coherent temporal dynamics, remains largely underexplored. Moreover, existing STVSR methods predominantly address spatiotemporal upsampling under simplified degradation assumptions, which often struggle in real-world scenarios with complex unknown degradations. Such a high demand for reconstruction fidelity and temporal consistency makes the development of a robust STVSR framework particularly non-trivial. To address these challenges, we propose OSDEnhancer, a novel framework that, to the best of our knowledge, represents the first method to achieve real-world STVSR through an efficient one-step diffusion process. OSDEnhancer initializes essential spatiotemporal structures through a linear pre-interpolation strategy and pivots on training temporal refinement and spatial enhancement mixture of experts (TR-SE MoE), which allows distinct expert pathways to progressively learn robust, specialized representations for temporal coherence and spatial detail, further collaboratively reinforcing each other during inference. A bidirectional deformable variational autoencoder (VAE) decoder is further introduced to perform recurrent spatiotemporal aggregation and propagation, enhancing cross-frame reconstruction fidelity. Experiments demonstrate that the proposed method achieves state-of-the-art performance while maintaining superior generalization capability in real-world scenarios.
