The power of video over still images is the ability to represent dynamic activities. But video browsing and retrieval are inconvenient due to inherent spatio-temporal redundancies, where some time periods may have no activity, or have activities that occur only in a small image region. Video synopsis aims to provide a compact video representation, while preserving the essential activities of the original video.
In dynamic video synopsis, most of the activity in the video is condensed by simultaneously showing several actions, even when they originally occurred at different times. While the temporal compaction is made possible by compromising the chronological time between objects, the dynamics of each object is preserved in this process.
An exciting application for video synopsis is the summarization of infinite video streams, such as those produced by surveillance cameras. Given an endless video stream, a user can specify the period of interest and the desired length of the summary. For example he could request to view a summary of the last day in 30 seconds. This provides an efficient tool to browse the millions of surveillance cameras available today.