Research

Masked Motion Encoding for Self-Supervised Video Representation Learning

CVPR

Authors

  • Xinyu Sun
  • Peihao Chen
  • Liangwei Chen
  • Changhao Li
  • Thomas H. Li
  • Mingkui Tan
  • Chuang Gan

Published on

06/22/2023

Categories

CVPR

How to learn discriminative video representation from unlabeled videos is challenging but crucial for video analysis. The latest attempts seek to learn a representation model by predicting the appearance contents in the masked regions. However, simply masking and recovering appearance contents may not be sufficient to model temporal clues as the appearance contents can be easily reconstructed from a single frame. To overcome this limitation, we present Masked Motion Encoding (MME), a new pretraining paradigm that reconstructs both appearance and motion information to explore temporal clues. In MME, we focus on addressing two critical challenges to improve the representation performance: 1) how to well represent the possible long-term motion across multiple frames; and 2) how to obtain fine-grained temporal clues from sparsely sampled videos. Motivated by the fact that human is able to recognize an action by tracking objects’ position changes and shape changes, we propose to reconstruct a motion trajectory that represents these two kinds of change in the masked regions. Besides, given the sparse video input, we enforce the model to reconstruct dense motion trajectories in both spatial and temporal dimensions. Pre-trained with our MME paradigm, the model is able to anticipate longterm and fine-grained motion details. Code is available at https://github.com/XinyuSun/MME.

This work was presented at CVPR 2023.

Please cite our work using the BibTeX below.

@InProceedings{Sun_2023_CVPR,
    author    = {Sun, Xinyu and Chen, Peihao and Chen, Liangwei and Li, Changhao and Li, Thomas H. and Tan, Mingkui and Gan, Chuang},
    title     = {Masked Motion Encoding for Self-Supervised Video Representation Learning},
    booktitle = {Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR)},
    month     = {June},
    year      = {2023},
    pages     = {2235-2245}
}
Close Modal