Hierarchical Memory Modelling for Video Captioning

Translating videos into natural language sentences has drawn much attention recently. The framework of combining visual attention with Long Short-Term Memory (LSTM) based text decoder has achieved much progress. However, the vision-language translation still remains unsolved due to the semantic gap and misalignment between video content and described semantic concept. In this paper, we propose a Hierarchical Memory Model (HMM) - a novel deep video captioning architecture which unifies a textual memory, a visual memory and an attribute memory in a hierarchical way. These memories can guide attention for efficient video representation extraction and semantic attribute selection in addition to modelling the long-term dependency for video sequence and sentences, respectively. Compared with traditional vision-based text decoder, the proposed attribute-based text decoder can largely reduce the semantic discrepancy between video and sentence. To prove the effectiveness of the proposed model, we perform extensive experiments on two public benchmark datasets: MSVD and MSR-VTT. Experiments show that our model not only can discover appropriate video representation and semantic attributes but also can achieve comparable or superior performances than state-of-the-art methods on these datasets.