Similarity Graph Convolutional Construction Network for Interactive Action Recognition

Interaction action recognition is a challenging problem in the research of computer vision. Skeleton-based action recognition shows great performance in recent years, but the non-Euclidean distance structure of the skeleton brings a huge challenge to the design of deep learning neural network. When meeting interaction action recognition, research in the previous study is based on a fixed skeleton graph, capturing only information about local body movements in a single action and do not deal with the relationship between two or more people. In this article, we present a similarity graph convolutional network that contains two-person interaction information. This model can represent the relationship between two people. Simultaneously, for different body parts (such as head and hand), the relationship can be handled. The model has two construction modes, a skeleton graph and a similarity graph, and the features from the two composition modes is better fused by the hypergraph. Similarity graph is obtained from a two-step construction. First, an encoder is designed, which is aimed to map different characteristics of one joint to a same vector space. Second, we calculate the similarity between different joints to construct the similarity graph. Follow the steps above, similarity graph can indicate the relationship between two people in details. We perform experiments on the NTU RGB+D dataset and verify the effectiveness of our model. The result shows that our approach outperforms the state-of-the-art methods and similarity graph can solve the relationship modeling problem in interactive action recognition.