VideoZoom is a software tool developed by the JRC that uses image summaries and a zooming interface to enable the inspector’s ability to detect safeguards-relevant events, whether typical or anomalies. Inspectors see image details or context information on-demand.
Nuclear safeguards verify that a State’s nuclear material is not diverted in order to build weapons or explosive devices. Camera surveillance in nuclear facilities helps to attain safeguards at a low cost since it does not require the continuous presence of inspectors in the facilities. Nor does it interfere with day to day plant operations.
Surveillance streams contain thousands of images. Inspectors review them in order to find the safeguards-relevant events. The term ‘safeguards-relevant’ covers both operations expected during normal plant operation and possibly any irregular activities. Statistically less than 0.01% of the images in a stream are safeguards-relevant. Hence the need for tools to help focusing the inspectors’ attention directly to the relevant parts of the image stream.
The current approach to image reviews makes use of scene change detection (SCD) within areas of interest (AOIs). AOIs are locations where safeguards-relevant events are expected to take place given the process under review.
Filtering the image stream by AOIs reduces the SCD events to be reviewed. This can be effective for regular processes, but not for the irregular ones (if any) as these may take place outside expected AOIs.
Video Summarisation
The JRC designed the VideoZoom prototype for image reviews removing the ‘Area of Interest assumption of relevance’. VideoZoom detects scene changes on the whole image plane. Because changes are too numerous to be seen one-by-one at a photographic level, they are summarised and rendered at different levels of abstraction. The image architecture is made of four layers of summaries, each one revealing more information about the image changes. The last layer of a summary is a video play of the images as taken by the camera.
Zooming interface
On the storyboard a zooming interface allows the reviewer to navigate the summary layers and decide which are to be viewed with full photographic detail and, conversely, which can be skipped because of clear no safeguards-relevance. In this way reviewers can make best use of their time by investigating what really requires their attention.
Storyboard
During the image review the sequence of summaries is presented on screen like a storyboard. Summaries are ordered by time on a grid layout read left-right, top-down.
Future objectives
VideoZoom is being integrated into the official image review tool in use at DG ENER and at the IAEA by safeguards inspectors. On the research side the JRC will extend VideoZoom by real-time Machine Learning to further assist the nuclear inspector in the detection of safeguards–relevant events within video surveillance streams.
