FSTT: Flow-Guided Spatial Temporal Transformer for Deep Video Inpainting

Video inpainting aims to complete the missing regions with content that is consistent both spatially and temporally. How to effectively utilize the spatio-temporal information in videos is critical for video inpainting. Recent advances in video inpainting methods combine both optical flow and transformers to capture spatio-temporal information. However, these methods fail to fully explore the potential of optical flow within the transformer. Furthermore, the designed transformer block cannot effectively integrate spatio-temporal information across frames. To address the above problems, we propose a novel video inpainting model, named Flow-Guided Spatial Temporal Transformer (FSTT), which effectively establishes correspondences between missing regions and valid regions in both spatial and temporal dimensions under the guidance of completed optical flow. Specifically, a Flow-Guided Fusion Feed-Forward module is developed to enhance features with the assistance of optical flow, mitigating the inaccuracies caused by hole pixels when performing MHSA. Additionally, a decomposed spatio-temporal MHSA module is proposed to effectively capture spatio-temporal dependencies in videos. To improve the efficiency of the model, a Global–Local Temporal MHSA module is further designed based on the window partition strategy. Extensive quantitative and qualitative experiments on the DAVIS and YouTube-VOS datasets demonstrate the superiority of our proposed method.