Video synopsis

Fig 1: Screen shots: Before and after Video Synopsis. 9 hours of activity summarized in a 20-second simultaneous presentation of multiple objects and activities that occurred at different times.
Fig. 2: Tube packing - Schematic example: Creating the video summary by re-timing the space-time tubes, (X= the 2-dimensional XY axis of each frame).

Video synopsis (often abbreviated V.S.) is an approach to create a short video summary of a long video. It tracks and analyzes moving objects (also called events), and converts video streams into a database of objects and activities.[1] The technology has specific applications in the field of video surveillance where, despite technological advancements and increased growth in the deployment of CCTV (closed circuit television) cameras,[2] viewing and analysis of recorded footage is still a costly and labor-intensive and time-intensive task.

Technology overview

Video synopsis combines a visual summary of stored video together with an indexing mechanism.

When a summary is required, all objects from the target period are collected and shifted in time to create a much shorter synopsis video showing maximum activity. A synopsis video clip is generated, in real time, in which objects and activities that originally occurred in different times are displayed simultaneously.[3] (See Figure 1 - Screen shots: Before and after Video Synopsis).

The process begins by detecting and tracking objects of interest. Each object is represented as a "tube" in "space-time" of all video frames. Objects are detected and stored in a database in approximately real time.

Following a request to summarize a time period, all objects from the desired time are extracted from the database, and indexed to create a much shorter summary video containing maximum activity. (See Figure 2 - Tube packing).

Real time rendering is used to generate the summary video after object re-timing. This allows end-user control over object/event density.

Video Synopsis technology was invented by Prof. Shmuel Peleg[4] of The Hebrew University of Jerusalem, Israel, and is being developed under commercial license by BriefCam, Ltd.[5] BriefCam received a license to use the technology from Yissum which is the owner of the patents registered for the technology.

Video Synopsis before+after (horizontal).jpg

Recent Advances

Recent advances in the field of Video Synopsis have resulted in methods that focus in collecting key-points(or frames) from the long uncut video and presenting them as a chain of "key" events that summarize the video. As mentioned in,[6] this is only one of the many methods employed in modern literature to perform this task. Recently, these event-driven methods have focused on correlating objects in frames, but in a more semantically related way that has been called a story-driven method of summarizing video. These methods have been shown to work well for egocentric[7] settings where the video is basically a point-of-view perspective of a single person or a group of people.

See also

References

  1. ↑ Y. Pritch, S. Ratovitch, A. Hendel, and S. Peleg, Clustered Synopsis of Surveillance Video, 6th IEEE Int. Conf. on Advanced Video and Signal Based Surveillance (AVSS'09), Genoa, Italy, Sept. 2-4, 2009
  2. ↑ Y. Pritch, A. Rav-Acha, A. Gutman, and S. Peleg, Webcam Synopsis: Peeking Around the World, ICCV'07, October 2007. 8p.
  3. ↑ Y. Pritch, A. Rav-Acha, and S. Peleg, Nonchronological Video Synopsis and Indexing, IEEE Trans. PAMI, Vol 30, No 11, Nov. 2008, pp. 1971-1984.
  4. ↑ A. Rav-Acha, Y. Pritch, and S. Peleg, Making a Long Video Short: Dynamic Video Synopsis, CVPR'06, June 2006, pp. 435-441.
  5. ↑ S. Peleg, Y. Caspi, BriefCam White Paper
  6. ↑ Muhammad Ajmal, Muhammad Husnain Ashraf, Muhammad Shakir, Yasir Abbas, Faiz Ali Shah, Video Summarization: Techniques and Classification
  7. ↑ Zheng Lu, Kristen Grauman Story-driven summarization for egocentric video. In Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition - 2013.

Patents

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