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arXiv · 2104.14558

A Large-Scale Study on Unsupervised Spatiotemporal Representation Learning

Christoph Feichtenhofer·Haoqi Fan·Bo Xiong·Ross Girshick·Kaiming He
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Abstract

We present a large-scale study on unsupervised spatiotemporal representation learning from videos. With a unified perspective on four recent image-based frameworks, we study a simple objective that can easily generalize all these methods to space-time. Our objective encourages temporally-persistent features in the same video, and in spite of its simplicity, it works surprisingly well across: (i) different unsupervised frameworks, (ii) pre-training datasets, (iii) downstream datasets, and (iv) backbone architectures. We draw a series of intriguing observations from this study, e.g., we discover that encouraging long-spanned persistency can be effective even if the timespan is 60 seconds. In addition to state-of-the-art results in multiple benchmarks, we report a few promising cases in which unsupervised pre-training can outperform its supervised counterpart. Code is made available at https://github.com/facebookresearch/SlowFast

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Christoph Feichtenhofer, Haoqi Fan, Bo Xiong, Ross Girshick, Kaiming He. 2021-04-29. A Large-Scale Study on Unsupervised Spatiotemporal Representation Learning. https://arxiv.org/abs/2104.14558

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