Detection of Event of Interest for Satellite Video Understanding

Satellite videos provide rich dynamic information of observed scenes at a large spatial and temporal scale and will play an important role in the future space information network. This work devotes to revealing events of interest (EOI) from satellite video scenes by using a two-stream method. In satellite videos, individual frames reflect the static information like the basic scenes where the event was happening, while a sequence of frames determines the motion information. Considering these facts, a novel two-stream EOI detection framework is proposed, where one stream extracts static spatial information of satellite videos by AlexNet, whereas the other stream extracts the motion information using a local trajectories analysis method. First, the whole video scene is segmented into small spatial-temporal patches, where labeling EOI and non-EOI is completed. Next, the trajectories are extracted from 3-D satellite video cubes that are generated from event scene patches. Finally, this trajectory classification process is treated as a weak supervision learning problem and solved by sparse dictionary learning. The experimental results demonstrate that the proposed two-stream method is effective for EOI detection and has a huge potential for satellite video scenes analysis and understanding. The proposed method also outperforms the existing competitive models for video analysis.