This module detects surprising events in the live video feed from the camera, and records short video clips of each detected event.

Surprising is here defined according to Itti and Baldi's mathematical theory of surprise (see, e.g., http://ilab.usc.edu/surprise/) which is applied to monitoring live video streams. When a surprising event is detected, a short video clip of that event is saved to the microSD card inside JeVois, for later review.

It was created in this JeVois tutorial: http://jevois.org/tutorials/ProgrammerSurprise.html

Using this module

This module does not send any video output to USB. Rather, it just saves surprising events to microSD for later review. Hence, you may want to try the following:

• mount the JeVois camera where you want it to detect surprising events
• run it connected to a laptop computer, using any mode which does have some video output over USB (e.g., 640x500 YUYV). Adjust the camera orientation to best fit your needs.
• edit JEVOIS:/config/initscript.cfg to contain:

    setmapping2 YUYV 640 480 15.0 JeVois SurpriseRecorder
    setpar thresh 1e7
    setpar channels S
    streamon

  and see the above tutorial for more details. Next time you power JeVois, it will immediately start detecting and recording surprising events in its view.

Example

Here is one hour of video surveillance footage. It is very boring overall. Except that a few brief surprising things occur (a few seconds each). Can you find them?

Here is what the SurpriseRecorder module found (4 true events plus 2 false alarms):

With only 6 surprising events, and assuming +/- 10 seconds of context frames around each event, we have achieved a compression of the surveillance footage from 60 minutes to 2 minutes (a factor 30x).