🤖 AI Summary
Unsupervised disentanglement of static appearance and dynamic motion in videos suffers from inter-factor information leakage and reconstruction ambiguity. This paper proposes the first end-to-end video diffusion framework that employs a sequence encoder to separately extract global static features and frame-wise dynamic features, followed by a conditional denoising diffusion model for high-fidelity decomposition. Innovatively integrating diffusion models into explicit static-dynamic factorization, we introduce three novel components: (i) a shared noise schedule across factors, (ii) a time-varying KL bottleneck to constrain temporal dynamics, and (iii) orthogonal regularization to enforce feature independence. Evaluated on real-world benchmarks, our method achieves state-of-the-art static fidelity and dynamic transferability, with the lowest cross-factor leakage rate and highest joint swap accuracy—demonstrating superior disentanglement quality and generalization.
📝 Abstract
Unsupervised disentanglement of static appearance and dynamic motion in video remains a fundamental challenge, often hindered by information leakage and blurry reconstructions in existing VAE- and GAN-based approaches. We introduce DiViD, the first end-to-end video diffusion framework for explicit static-dynamic factorization. DiViD's sequence encoder extracts a global static token from the first frame and per-frame dynamic tokens, explicitly removing static content from the motion code. Its conditional DDPM decoder incorporates three key inductive biases: a shared-noise schedule for temporal consistency, a time-varying KL-based bottleneck that tightens at early timesteps (compressing static information) and relaxes later (enriching dynamics), and cross-attention that routes the global static token to all frames while keeping dynamic tokens frame-specific. An orthogonality regularizer further prevents residual static-dynamic leakage. We evaluate DiViD on real-world benchmarks using swap-based accuracy and cross-leakage metrics. DiViD outperforms state-of-the-art sequential disentanglement methods: it achieves the highest swap-based joint accuracy, preserves static fidelity while improving dynamic transfer, and reduces average cross-leakage.