The Law Enforcement and Emergency Services Video Association (LEVA) held it’s annual conference this week. I was fortunate to attend the two day pre-conference workshop on reverse projection photogrammetry presented by Richard Vorder Bruegge, Walter Bruehs, and Chris Iber, all from the FBI Forensic Audio, Video, and Imaging Analysis Unit.

Reverse Projection Photogrammetry is used to measure objects in a photograph or video. It can be used to determine if an individual could be excluded or included as a suspect based on height. In addition to using this method to determine the height of an individual in an image, I have used this technique to determine the position of objects in relation to their surroundings (after the objects were removed), the distance of safety barriers in construction scenes (after the construction was completed and the barriers removed), the size of cracks in a sidewalk (after the sidewalk was repaired), etc. from photos of those scenes.

The workshop covered issues related to the methodology and foundations of this technique. Any forensic image analyst or forensic video analyst who hasn’t yet had the opportunity to take this workshop should do so. It has been offered at the LEVA conference for two or three years, and also at the IAI Annual Conference.