Multi-level Attentive Adversarial Learning with Temporal Dilation for Unsupervised Video Domain Adaptation

Most existing works on unsupervised video domain adaptation attempt to mitigate the distribution gap across domains in frame and video levels. Such two-level distribution alignment approach may suffer from the problems of insufficient alignment for complex video data and misalignment along the temporal dimension. To address these issues, we develop a novel framework of Multi-level Attentive Adversarial Learning with Temporal Dilation (MA(2)L-TD). Given frame-level features as input, multi-level temporal features are generated and multiple domain discriminators are individually trained by adversarial learning for them. For better distribution alignment, level-wise attention weights are calculated by the degree of domain confusion in each level. To mitigate the negative effect of misalignment, features are aggregated with the attention mechanism determined by individual domain discriminators. Moreover, temporal dilation is designed for sequential non-repeatability to balance the computational efficiency and the possible number of levels. Extensive experimental results show that our proposed method outperforms the state of the art on four benchmark datasets.(1)