arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1803.09092cs.CV
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视频运动动态无监督学习的对抗框架

Adversarial Framework for Unsupervised Learning of Motion Dynamics in Videos

University of Catania(卡塔尼亚大学);University of Central Florida(中佛罗里达大学)

C. Spampinato, S. Palazzo, P. D'Oro, D. Giordano, M. Shah

摘要:

视频中的人类行为理解是一个复杂的、尚未解决的问题,需要在局部(像素级密集预测)和全局(运动线索的聚合)级别上准确地对运动进行建模。目前基于监督学习的方法需要大量的注释数据,其稀缺的可用性是开发通用解决方案的主要限制因素之一。相反,无监督学习可以利用网络上大量的视频,这是克服现有限制的一个很有前途的解决方案。在本文中,我们提出了一个基于对抗性GAN的框架,该框架通过自我监督机制学习视频表示和动态,以便在视频中执行密集和全局预测。我们的方法通过以下方式合成视频:1)将该过程分解为静态视觉内容和运动的生成,2)学习运动潜在空间的适当表示,以加强对象轨迹的时空一致性,以及3)将运动估计和像素密集预测纳入训练过程。通过使用由生成器产生的运动掩模作为其生成过程的副产品来执行自我监督,以监督网络执行密集预测。性能评估,进行标准的基准测试,表明我们的方法是能够学习,在一个无监督的方式,本地和全球的视频动态。学习的表示,然后,支持视频对象分割方法的训练与合理较少(约50%)的注释,使性能相当于最先进的国家。此外,所提出的方法在生成逼真的视频,表现优于最先进的方法,特别是在运动相关的指标。

英文摘要:

Human behavior understanding in videos is a complex, still unsolved problem and requires to accurately model motion at both the local (pixel-wise dense prediction) and global (aggregation of motion cues) levels. Current approaches based on supervised learning require large amounts of annotated data, whose scarce availability is one of the main limiting factors to the development of general solutions. Unsupervised learning can instead leverage the vast amount of videos available on the web and it is a promising solution for overcoming the existing limitations. In this paper, we propose an adversarial GAN-based framework that learns video representations and dynamics through a self-supervision mechanism in order to perform dense and global prediction in videos. Our approach synthesizes videos by 1) factorizing the process into the generation of static visual content and motion, 2) learning a suitable representation of a motion latent space in order to enforce spatio-temporal coherency of object trajectories, and 3) incorporating motion estimation and pixel-wise dense prediction into the training procedure. Self-supervision is enforced by using motion masks produced by the generator, as a co-product of its generation process, to supervise the discriminator network in performing dense prediction. Performance evaluation, carried out on standard benchmarks, shows that our approach is able to learn, in an unsupervised way, both local and global video dynamics. The learned representations, then, support the training of video object segmentation methods with sensibly less (about 50%) annotations, giving performance comparable to the state of the art. Furthermore, the proposed method achieves promising performance in generating realistic videos, outperforming state-of-the-art approaches especially on motion-related metrics.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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