Surveillance Cameras: Inside Looking Out


Laurence R. Penn, Senior Forensic Animation/Video Specialist



There’s a good chance an interior surveillance camera located close to a window will capture activity or an incident outside of the property it is primarily intended to surveil. Such was the case when a surveillance camera observing the entrance of a store captured a collision where a right turning truck collided with a cyclist traveling the same direction on a narrow city street. In fact, there were many cameras that captured the incident, including three cameras from two different businesses and the dashcam on the truck itself.
Videogrammetry techniques were used to camera match one of the surveillance videos to high resolution 3D scan data of the site. The truck was also documented, and its 3D data used to re-create a trajectory as depicted in the surveillance video. Videogrammetry analysis of the other cameras helped confirm the results of the vehicle tracking.
A photo of the scene was also camera matched to the 3D scan data using photogrammetry, confirming the point of rest of the vehicle. This type of analysis can prove invaluable when it comes to determining speeds and positions of the objects captured in the video frame. The results of a videogrammetric analysis can be used to further recreate an incident with 3D engineering animations and interactive virtual reality applications, like the one below. With the use of this technology, one can be placed in the driver’s seat to bear witness to the circumstances of the event and gain a better understanding of the situation.
Laurence R. Penn, Senior Forensic Animation/Video Specialist with DJS Associates, Inc., can be reached via email at or via phone at 215-659-2010.

Categories: Surveillance Cameras

Tags: Laurence R. Penn | Surveillance Cameras


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