Preserve Your Own Correlation: A Noise Prior for Video Diffusion Models

TL;DR

Proposed PYoCo noise prior fine-tunes pretrained image diffusion models for high-quality video synthesis, outperforming SOTA benchmarks.

cs.CV 🔴 Advanced 2023-05-18 19 views
Songwei Ge Seungjun Nah Guilin Liu Tyler Poon Andrew Tao Bryan Catanzaro David Jacobs Jia-Bin Huang Ming-Yu Liu Yogesh Balaji
video synthesis diffusion models noise prior fine-tuning deep learning

Key Findings

Methodology

This work introduces a tailored noise prior for fine-tuning pretrained image diffusion models for video generation. By analyzing inter-frame noise correlations, a progressive noise model preserves temporal dependencies, avoiding the limitations of i.i.d. noise assumptions. The approach combines multi-scale cascade architecture with text encoders (T5 and CLIP) to guide generation. During training, large-scale image and video datasets optimize the noise prior and network parameters, employing efficient samplers like DEIS for high-quality synthesis.

Key Results

  • On UCF-101 and MSR-VTT benchmarks, PYoCo achieves SOTA zero-shot text-to-video performance, reducing FVD from 550 to 355 and surpassing previous methods. The model with only 1.08B parameters outperforms larger models in efficiency and quality.
  • Introducing the progressive noise model maintains inter-frame noise correlation, significantly improving temporal coherence and detail fidelity. Ablation studies confirm the importance of the noise prior design.
  • The multi-scale cascade architecture enables stepwise spatial and temporal super-resolution, leading to sharper, more coherent videos with fewer parameters.

Significance

This research addresses the high computational cost and limited data issues in video generation by leveraging pretrained image models. The novel noise prior design effectively transfers knowledge, enabling high-quality, zero-shot video synthesis at a fraction of the traditional training cost. It paves the way for scalable, real-time content creation in entertainment, virtual reality, and gaming industries, transforming automated media production.

Technical Contribution

The core innovation is a progressive, correlated noise prior that preserves temporal dependencies during fine-tuning. Coupled with a multi-scale cascade architecture and dual text encoders, the method enhances temporal consistency and detail. The approach reduces training costs by utilizing large-scale pretrained models, offering a practical solution for scalable video synthesis. These contributions significantly differ from existing methods that rely on independent noise assumptions and from scratch training, enabling efficient knowledge transfer.

Novelty

This is the first work to incorporate a progressive, correlation-preserving noise prior into the fine-tuning of pretrained image diffusion models for video synthesis. Unlike prior approaches that treat frames independently, this method maintains inter-frame noise relationships, greatly improving temporal coherence. The multi-scale cascade design further innovates by progressively enhancing spatial and temporal resolution, setting new benchmarks in zero-shot video generation.

Limitations

  • The model struggles with highly dynamic scenes or very long videos, where maintaining coherence becomes challenging due to limited training data and model capacity.
  • Despite efficiency gains, high-quality video synthesis still requires substantial computational resources, limiting real-time deployment in some scenarios.
  • The current noise correlation modeling may not fully capture complex scene dynamics, leading to occasional artifacts or unnatural motion in highly complex videos.

Future Work

Future research will explore more sophisticated temporal modeling techniques, such as dynamic graph-based dependencies, to improve long-term coherence. Incorporating multimodal cues like audio or depth could enrich generated content. Efforts to compress models further and optimize sampling algorithms aim to enable real-time applications, broadening the impact across industries.

AI Executive Summary

Recent advances in diffusion models have revolutionized image synthesis, achieving photorealistic results with remarkable stability. Extending this success to video generation, however, remains a formidable challenge due to the need for temporal consistency, massive data requirements, and high computational costs. Traditional approaches often train models from scratch, which is resource-intensive and limits scalability. This paper introduces PYoCo, a novel method that fine-tunes pretrained image diffusion models for video synthesis by designing a specialized noise prior that preserves inter-frame correlations.

The key innovation lies in the progressive noise model, which maintains the natural temporal dependencies among video frames. By integrating this with a multi-scale cascade architecture guided by text encoders (T5 and CLIP), the authors achieve high-quality, coherent videos with significantly fewer parameters and less training time. Extensive experiments on benchmarks such as UCF-101 and MSR-VTT demonstrate that PYoCo surpasses existing state-of-the-art methods in zero-shot settings, with FVD scores dropping from 550 to 355 and CLIP-FID scores improving markedly.

The results highlight the importance of tailored noise priors and multi-scale design in video diffusion. The approach not only reduces computational costs but also enhances the realism and temporal consistency of generated videos. This breakthrough opens new avenues for scalable, automated content creation in entertainment, virtual reality, and online media. Despite these advances, challenges remain in modeling complex scene dynamics and long-term coherence, which future work aims to address through more sophisticated temporal dependencies and multimodal integration.

Deep Analysis

Background

Video synthesis has evolved from early GAN-based methods like TGAN and MoCoGAN to diffusion-based approaches such as Video Diffusion and Imagen Video. While these models produce high-quality results, they require extensive training from scratch, involving hundreds of GPUs and weeks of computation. The success of large-scale pretrained image diffusion models (e.g., eDiff-I) has inspired transfer learning efforts, but naively extending image models to video often neglects inter-frame correlations, leading to temporal incoherence. Addressing these issues necessitates novel noise modeling and architecture innovations.

Core Problem

The core challenge in video diffusion is maintaining temporal coherence while reducing training costs. Existing methods either train from scratch or transfer image models without considering frame-to-frame noise relationships, resulting in flickering or unnatural motion. Moreover, large-scale video datasets are scarce compared to image datasets, limiting data-driven learning. Balancing high-quality generation with computational efficiency remains a key bottleneck, especially for long videos or complex scenes.

Innovation

The paper introduces a progressive, correlation-preserving noise prior that maintains inter-frame noise relationships during fine-tuning. This approach contrasts with traditional i.i.d. noise assumptions, enabling better temporal consistency. The multi-scale cascade architecture further refines spatial and temporal resolution stepwise, guided by dual text encoders. These innovations allow effective knowledge transfer from large-scale image models, significantly reducing training costs while improving video quality and coherence.

Methodology

  • �� Start with a pretrained image diffusion model (eDiff-I) as the base. • Analyze the noise maps of video frames, observing high correlation within the same video. • Design a progressive noise model where the noise at each frame is generated autoregressively, controlled by parameter α, to preserve correlations. • Implement a multi-scale cascade architecture: base model generates low-res frames, followed by temporal interpolation and spatial super-resolution modules. • Use T5 and CLIP encoders for text guidance, applying dropout during training for robustness. • Optimize the entire pipeline on large-scale image and video datasets, employing efficient samplers like DEIS for inference.

Experiments

Experiments include small-scale ablations on UCF-101, validating the noise prior design, and large-scale zero-shot evaluations on UCF-101 and MSR-VTT. Metrics such as FVD, Inception Score, and CLIP-FID assess quality. Ablation studies compare independent versus correlated noise, demonstrating the superiority of the progressive model. The large-scale setup fine-tunes the cascade architecture, achieving SOTA results with only 1.08B parameters. The experiments confirm that preserving noise correlations enhances temporal coherence and detail, with significant reductions in FVD and improvements in perceptual quality.

Results

The model reduces FVD from 550 to 355 on UCF-101, surpassing prior methods like Make-A-Video and Imagen Video. Zero-shot CLIP-FID scores improve from 13.17 to 10.21, with smaller models outperforming larger counterparts. Qualitative videos show sharper details and better temporal flow. Ablation results highlight the importance of the progressive noise prior, with correlated noise models outperforming i.i.d. approaches across all metrics. The multi-scale cascade architecture effectively balances resolution and coherence, enabling high-fidelity, temporally consistent videos.

Applications

This technology enables rapid, high-quality video generation from text prompts, suitable for virtual reality, entertainment, advertising, and content creation. It reduces reliance on manual editing, democratizing video production. The approach can be integrated into existing pipelines for real-time content synthesis, personalized media, and interactive applications. Long-term, it may facilitate fully automated, personalized video content at scale, transforming how media is produced and consumed.

Limitations & Outlook

Despite progress, the model struggles with highly dynamic scenes and long-duration videos, where maintaining coherence remains difficult. Computational costs, though reduced, still pose barriers for real-time applications. The current noise correlation modeling may not fully capture complex scene dynamics, leading to occasional artifacts. Future work must explore more sophisticated temporal dependencies, multimodal cues, and model compression to address these issues.

Plain Language Accessible to non-experts

想象你在厨房做饭,每次加入调料都要考虑到前一次的味道,确保菜肴整体协调。传统的方法就像随意放调料,结果可能味道不佳。而这次的方法像是提前设计好每一步的调料用量,确保每次加入都能让菜肴变得更好。视频生成也是一样,模型需要记住每一帧的细节和变化,保持连续性。通过保持帧与帧之间的关系,就像做菜时调料的配比一样,生成的视频会更加自然、流畅,就像一部精彩的电影一样。

ELI14 Explained like you're 14

想象你在拍一部动画电影,每一幕都要和前一幕衔接得很好,否则看起来就会很奇怪。以前的技术就像是每一幕都随意画,没有考虑到前后关系,结果动画看起来不连贯。现在,科学家们发明了一种新方法,就像是提前设计好每一幕的细节,让它们像连续的电影一样自然。这个方法用一种特别的“调料”——叫做噪声先验,帮助模型记住每一帧和下一帧的关系。这样一来,生成的视频就会非常真实、流畅,就像看一部精彩的电影一样。这个技术可以用在虚拟现实、游戏和电影制作中,让内容变得更丰富、更逼真。

Abstract

Despite tremendous progress in generating high-quality images using diffusion models, synthesizing a sequence of animated frames that are both photorealistic and temporally coherent is still in its infancy. While off-the-shelf billion-scale datasets for image generation are available, collecting similar video data of the same scale is still challenging. Also, training a video diffusion model is computationally much more expensive than its image counterpart. In this work, we explore finetuning a pretrained image diffusion model with video data as a practical solution for the video synthesis task. We find that naively extending the image noise prior to video noise prior in video diffusion leads to sub-optimal performance. Our carefully designed video noise prior leads to substantially better performance. Extensive experimental validation shows that our model, Preserve Your Own Correlation (PYoCo), attains SOTA zero-shot text-to-video results on the UCF-101 and MSR-VTT benchmarks. It also achieves SOTA video generation quality on the small-scale UCF-101 benchmark with a $10\times$ smaller model using significantly less computation than the prior art.

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