EVU XXVII 2018 – 30 Using a 3D Point Cloud in the Analysis of CCTV Footage
Using a 3D Point Cloud
in the Analysis of CCTV Footage
The paper demonstrates a practical and easy method of producing a 3D point cloud using the Agisoft photogrammetry program, to generate a base plan for the analysis of CCTV footage.
An explanation of how to view CCTV footage as individual frames in Avidemux is explained, so that a vehicle’s position in time and space can be determined.
A point cloud can be imported into PC Crash and the camera position optimised, and thereafter a 3D model of the vehicle introduced and synchronised with the actual position of the vehicle in the CCTV footage.
Using 2 or more frames and defining the position of the vehicle in the 2D window, it is possible to determine an approximation of the distance covered in time and hence the vehicle’s speed by reference to the 3D model in the 3D window.
Using this procedure, based on Freeware or inexpensive Software, the accident investigator can quickly and accurately estimate the vehicle speed from CCTV footage.
La lettura di questo articolo è riservata ai soli Soci EVU Italia.