Title
Temporally-Weighted Hierarchical Clustering for Unsupervised Action Segmentation
Abstract
Action segmentation refers to inferring boundaries of semantically consistent visual concepts in videos and is an important requirement for many video understanding tasks. For this and other video understanding tasks, supervised approaches have achieved encouraging performance but require a high volume of detailed frame-level annotations. We present a fully automatic and unsupervised approach for segmenting actions in a video that does not require any training. Our proposal is an effective temporally-weighted hierarchical clustering algorithm that can group semantically consistent frames of the video. Our main finding is that representing a video with a 1-nearest neighbor graph by taking into account the time progression is sufficient to form semantically and temporally consistent clusters of frames where each cluster may represent some action in the video. Additionally, we establish strong unsupervised baselines for action segmentation and show significant performance improvements over published unsupervised methods on five challenging action segmentation datasets. Our code is available.
Year
DOI
Venue
2021
10.1109/CVPR46437.2021.01107
2021 IEEE/CVF CONFERENCE ON COMPUTER VISION AND PATTERN RECOGNITION, CVPR 2021
DocType
ISSN
Citations 
Conference
1063-6919
0
PageRank 
References 
Authors
0.34
0
6
Name
Order
Citations
PageRank
M. Saquib Sarfraz111811.60
Naila Murray21457.64
Vivek Sharma3154.92
Ali Diba4533.42
Luc Van Gool5275661819.51
Rainer Stiefelhagen63512274.86