Video Projection Mapping Photogrammetry through Video Tracking

This paper examines a method for generating a scaled three-dimensional computer model of an accident scene from video footage. This method, which combines the previously published methods of video tracking and camera projection, includes automated mapping of physical evidence through rectification of each frame. Video Tracking is a photogrammetric technique for obtaining three-dimensional data from a scene using video and was described in a 2004 publication titled, “A Video Tracking Photogrammetry Technique to Survey Roadways for Accident Reconstruction” (SAE 2004-01-1221). That paper described a method for generating a three-dimensional computer model of a roadway by using video of a drive-through of an accident scene and processing this video footage through available video tracking software.^1,2 The benefit of being able to drive through an accident scene to collect data lies in the speed of such a method, but also in safety, as some accident areas are too heavy with traffic, dangerous or otherwise inaccessible. Three-dimensional Camera Projection Mapping is a computer visualization technique of wrapping or mapping video or photographs onto three-dimensional geometry and adjusting the size and shape of the map so it follows the size and shape of the target objects. This rectification process results in a photo-realistic computer model that is accurate in detail, lighting and scale since it is built directly from the photograph. The result of adding the technology of video tracking with three-dimensional camera projection mapping is a scaled computer model of the accident scene that includes photographs of the evidence mapped onto the geometry at the correct scale and location - all from a single video drive-through. Developing both of these concepts into one method of Video Projection Mapping combines the ease of building a three-dimensional accident diagram from a video drive-through, with the accuracy and clarity of analyzing scaled photographic data.