Papers › CT-Net: Channel Tensorization Network for Video Classification

CT-Net: Channel Tensorization Network for Video Classification

3 Jun 2021ICLR 2021 1arXiv:2106.01603archive 2025-07-28

Kunchang Li, Xianhang Li, Yali Wang, Jun Wang, Yu Qiao

3D convolution is powerful for video classification but often computationally expensive, recent studies mainly focus on decomposing it on spatial-temporal and/or channel dimensions. Unfortunately, most approaches fail to achieve a preferable balance between convolutional efficiency and feature-interaction sufficiency. For this reason, we propose a concise and novel Channel Tensorization Network (CT-Net), by treating the channel dimension of input feature as a multiplication of K sub-dimensions. On one hand, it naturally factorizes convolution in a multiple dimension way, leading to a light computation burden. On the other hand, it can effectively enhance feature interaction from different channels, and progressively enlarge the 3D receptive field of such interaction to boost classification accuracy. Furthermore, we equip our CT-Module with a Tensor Excitation (TE) mechanism. It can learn to exploit spatial, temporal and channel attention in a high-dimensional manner, to improve the cooperative power of all the feature dimensions in our CT-Module. Finally, we flexibly adapt ResNet as our CT-Net. Extensive experiments are conducted on several challenging video benchmarks, e.g., Kinetics-400, Something-Something V1 and V2. Our CT-Net outperforms a number of recent SOTA approaches, in terms of accuracy and/or efficiency. The codes and models will be available on https://github.com/Andy1621/CT-Net.

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ChannelGroupAttention Andy1621/CT-Net/ops/reshape_block.py official repository ran MIT (permissive) · 6260211e3787baa5 · report
TemporalGroupAttention Andy1621/CT-Net/ops/reshape_block.py official repository ran MIT (permissive) · aee433c108b8ad52 · report
conv_1x1_bn Andy1621/CT-Net/ops/reshape_block.py official repository ran · our draft was wrong MIT (permissive) · c455a6669e2554a5 · report
conv_1x1x1 Andy1621/CT-Net/ops/reshape_block.py official repository ran · our draft was wrong MIT (permissive) · ec968a25ec7aef0f · report
conv_1x1x1_bn Andy1621/CT-Net/ops/reshape_block.py official repository ran · our draft was wrong MIT (permissive) · c2f0baed989321b4 · report
conv_1x3x3 Andy1621/CT-Net/ops/reshape_block.py official repository ran · our draft was wrong MIT (permissive) · 537b6a478a291bb6 · report
conv_1x3x3_bn Andy1621/CT-Net/ops/reshape_block.py official repository ran · our draft was wrong MIT (permissive) · ed910e0667f0eb1e · report
conv_3x1x1 Andy1621/CT-Net/ops/reshape_block.py official repository ran · our draft was wrong MIT (permissive) · 2b0d4f8ad8c45d75 · report
conv_3x1x1_bn Andy1621/CT-Net/ops/reshape_block.py official repository ran · our draft was wrong MIT (permissive) · 951a6b522747450c · report
get_xy Andy1621/CT-Net/ops/reshape_block.py official repository ran · honoured contract fingerprinted MIT (permissive) · ca18d92d71a013ef · report
ReshapeBlock Andy1621/CT-Net/ops/reshape_block.py official repository unverified MIT (permissive) · b66d42a805e6085e · report
ReshapeInteraction Andy1621/CT-Net/ops/reshape_block.py official repository unverified MIT (permissive) · 9d7ca7fd0b4939d3 · report
SpatialGroupAttention Andy1621/CT-Net/ops/reshape_block.py official repository unverified MIT (permissive) · 6bcaa5143e16e1ab · report

Tasks

Action ClassificationAction RecognitionClassificationVideo Classification

Results from the paper archive 2025-07-28

TaskDatasetModelMetricValueRank at snapshotLeaderboardReport
Action Classification Kinetics-400 CT-Net Ensemble Acc@1 79.8 #106 of 207 Archive leaderboard report
Action Recognition Something-Something V1 CT-Net Ensemble (R50, 8+12+16+24) Top 1 Accuracy 56.6 #20 of 74 Archive leaderboard report
Action Recognition Something-Something V2 CT-Net Ensemble (R50, 8+12+16+24) GFLOPs 280 #59 of 123 Archive leaderboard report
Action Recognition Something-Something V2 CT-Net Ensemble (R50, 8+12+16+24) Parameters 83.8 #59 of 123 Archive leaderboard report
Action Recognition Something-Something V2 CT-Net Ensemble (R50, 8+12+16+24) Top-1 Accuracy 67.8 #59 of 123 Archive leaderboard report
Action Recognition Something-Something V2 CT-Net Ensemble (R50, 8+12+16+24) Top-5 Accuracy 91.1 #59 of 123 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

1x1 ConvolutionAverage PoolingBatch NormalizationBottleneck Residual BlockConvolutionGlobal Average PoolingKaiming InitializationMax PoolingReLUResidual BlockResidual Connection

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