Stereo-image capture tool for forensic mapping of surveillance video footage

Abstract

This paper discusses the evaluation of a video stereo-image capture tool for photogrammetric applications. The 'NuView Stereo Adapter', a stereo-imaging device and a high-definition video HDV) were used to capture stereoscopic video footage. The HDV video becomes a complete stereo-imaging system when stereo adapter is mounted onto video lens barrel and could be used to capture stereoscopic video footage for many photogrammetric applications. Relevant photogrammetric applications might include: motion study, 3D animation and aerial/security surveillance. The device permits two distinct views (left and right perspective views) to enter a single lens HDV. A single convergence control in the device allows the user to obtain a stereo view of near and far objects. The system is easy to operate and the stereo-images give a good visual 3D effect. Research was carried out to determine the quality of the stereo-image for 3D measurement. The investigation involved: (1) the calibrations of a customized system for optimum close range photogrammetric application; and (2) a case study involving forensic mapping of surveillance video footage. A semi-automated and manual monodigitising photogrammetric technique was used to determine the accuracy of the system. The results of the research show that the system is capable of obtaining spatial data with 10 mm accuracy using a single video camera. As the resolution of an off-the-shelf video camera is high, the video footage can achieve 30 mm accuracy under 5 m object distance.