TAM - Temporal Adaptive Module for Video Recognition.

Temporal modeling is crucial for capturing spatiotemporal structure in videos for action recognition. Video data is with extremely complex dynamics along temporal dimension due to various factors such as camera motion, speed variation, and different activities. To effectively capture this diverse motion pattern, this paper presents a new temporal adaptive module (TAM) to generate video-specific kernels based on its own feature maps. TAM proposes a unique two-level adaptive modeling scheme by decoupling dynamic kernels into a location insensitive importance map and a location invariant aggregation weight. The importance map is learned in a local temporal window to capture short term information, while the aggregation weight is generated from a global view with a focus on long-term structure. TAM is a principled module and could be integrated into 2D CNNs to yield a powerful video architecture (TANet) with a very small extra computational cost. The extensive experiments on Kinetics-400 demonstrate that TAM outperforms other temporal modeling methods consistently owing to its adaptive modeling strategy. On Something-Something datasets, TANet achieves superior performance compared with previous state-of-the-art methods. The code will be made available soon at https://github.com/liu-zhy/TANet.