Spatio-Temporal Graph Convolution Transformer for Video Question Answering

Currently, video question answering (VideoQA) algorithms relying on video-text pretraining models employ intricate unimodal encoders and multimodal fusion Transformers, which often lead to decreased efficiency in tasks such as visual reasoning. Conversely, video question answering algorithms based on graph neural networks often exhibit suboptimal performance in video description and reasoning, attributed to their simplistic graph construction and cross-modal interaction designs, necessitating additional pretraining data to mitigate these performance disparities. In this work, we introduce the Spatio-temporal Graph Convolution Transformer (STCT) model for VideoQA. By leveraging Spatio-temporal Graph Convolution (STGC) and dynamic graph Transformers, our model explicitly captures the spatio-temporal relationships among visual objects, thereby facilitating dynamic interactions and enhancing visual reasoning capabilities. Moreover, our model introduces a novel cross-modal interaction approach utilizing dynamic graph attention mechanisms to adjust the attention weights of visual objects based on the posed question, thereby augmenting multimodal cooperative perception. By addressing the limitations of graph-based algorithms dependent on pretraining for performance enhancement through meticulously designed graph structures and cross-modal interaction mechanisms, our model achieves superior performance in visual description and reasoning tasks with simpler unimodal encoders and multimodal fusion modules. Comprehensive analyses and comparisons of the model's performance across multiple datasets, including NExT-QA, MSVD-QA, and MSRVTT-QA datasets, have confirmed its robust capabilities in video reasoning and description.