Current methods for skeleton-based human action recognition usually work with completely observed skeletons. However, in real scenarios, it is prone to capture incomplete and noisy skeletons, which will deteriorate the performance of traditional models. To enhance the robustness of action recognition models to incomplete skeletons, we propose a multi-stream graph convolutional network (GCN) for exploring sufficient discriminative features distributed over all skeleton joints. Here, each stream of the network is only responsible for learning features from currently unactivated joints, which are distinguished by the class activation maps (CAM) obtained by preceding streams, so that the activated joints of the proposed method are obviously more than traditional methods. Thus, the proposed method is termed richly activated GCN (RA-GCN), where the richly discovered features will improve the robustness of the model. Compared to the state-of-the-art methods, the RA-GCN achieves comparable performance on the NTU RGB+D dataset. Moreover, on a synthetic occlusion dataset, the performance deterioration can be alleviated by the RA-GCN significantly.

本研究提出了富激活 GCN（RA-GCN）的多流图卷积网络，从尚未激活的关节中学习特征，以增强不完整骨架的动作识别模型的稳健性。与现有方法相比，RA-GCN在NTU RGB+D数据集上实现了可比较的性能，并显着减轻了虚拟遮挡数据集的性能下降。

基于不完整骨架的丰富激活图卷积神经网络动作识别