Papers › Video Classification with Channel-Separated Convolutional Networks

Video Classification with Channel-Separated Convolutional Networks

4 Apr 2019ICCV 2019 10arXiv:1904.02811archive 2025-07-28

Du Tran, Heng Wang, Lorenzo Torresani, Matt Feiszli

Group convolution has been shown to offer great computational savings in various 2D convolutional architectures for image classification. It is natural to ask: 1) if group convolution can help to alleviate the high computational cost of video classification networks; 2) what factors matter the most in 3D group convolutional networks; and 3) what are good computation/accuracy trade-offs with 3D group convolutional networks. This paper studies the effects of different design choices in 3D group convolutional networks for video classification. We empirically demonstrate that the amount of channel interactions plays an important role in the accuracy of 3D group convolutional networks. Our experiments suggest two main findings. First, it is a good practice to factorize 3D convolutions by separating channel interactions and spatiotemporal interactions as this leads to improved accuracy and lower computational cost. Second, 3D channel-separated convolutions provide a form of regularization, yielding lower training accuracy but higher test accuracy compared to 3D convolutions. These two empirical findings lead us to design an architecture -- Channel-Separated Convolutional Network (CSN) -- which is simple, efficient, yet accurate. On Sports1M, Kinetics, and Something-Something, our CSNs are comparable with or better than the state-of-the-art while being 2-3 times more efficient.

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Tasks

Action ClassificationAction RecognitionGeneral ClassificationImage ClassificationVideo Classificationimage-classification

Results from the paper archive 2025-07-28

TaskDatasetModelMetricValueRank at snapshotLeaderboardReport
Action Classification Kinetics-400 ir-CSN-152 (IG-65M pretraining) Acc@1 82.6 #75 of 207 Archive leaderboard report
Action Classification Kinetics-400 ip-CSN-152 (IG-65M pretraining) Acc@1 82.5 #76 of 207 Archive leaderboard report
Action Classification Kinetics-400 ip-CSN-152 (IG-65M pretraining) Acc@5 95.3 #76 of 207 Archive leaderboard report
Action Classification Kinetics-400 R[2+1]D-152 (IG-65M pretraining) Acc@1 81.3 #85 of 207 Archive leaderboard report
Action Classification Kinetics-400 R[2+1]D-152 (IG-65M pretraining) Acc@5 95.1 #85 of 207 Archive leaderboard report
Action Classification Kinetics-400 ip-CSN-152 (Sports-1M pretraining) Acc@1 79.2 #115 of 207 Archive leaderboard report
Action Classification Kinetics-400 ip-CSN-152 (Sports-1M pretraining) Acc@5 93.8 #115 of 207 Archive leaderboard report
Action Classification Kinetics-400 ip-CSN-152 Acc@1 77.8 #133 of 207 Archive leaderboard report
Action Classification Kinetics-400 ip-CSN-152 Acc@5 92.8 #133 of 207 Archive leaderboard report
Action Recognition Something-Something V1 ip-CSN-152 (IG-65M pretraining) Top 1 Accuracy 53.3 #38 of 74 Archive leaderboard report
Action Recognition Something-Something V1 ir-CSN-152 (IG-65M pretraining) Top 1 Accuracy 52.1 #45 of 74 Archive leaderboard report
Action Recognition Something-Something V1 R(2+1)D-152 (IG-65M pretraining) Top 1 Accuracy 51.6 #48 of 74 Archive leaderboard report
Action Recognition Something-Something V1 ir-CSN-152 Top 1 Accuracy 49.3 #58 of 74 Archive leaderboard report
Action Recognition Something-Something V1 ir-CSN-101 Top 1 Accuracy 48.4 #61 of 74 Archive leaderboard report
Action Recognition Sports-1M ip-CSN-152 (RGB) Video hit@1 75.5 #1 of 9 Archive leaderboard report
Action Recognition Sports-1M ip-CSN-152 (RGB) Video hit@5 92.8 #1 of 9 Archive leaderboard report
Action Recognition Sports-1M ip-CSN-101 (RGB) Video hit@1 74.9 #2 of 9 Archive leaderboard report
Action Recognition Sports-1M ip-CSN-101 (RGB) Video hit@5 92.6 #2 of 9 Archive leaderboard report

Ranks are positions in the archive's leaderboards as they stood at the 2025-07-28 snapshot. Results published since then are not among these rows, so a rank here is not a current standing.

Methods

Convolution

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