Traffic accident investigation by the police forensic science department in Thailand is essential to determine their causes.The collection of forensic evidence from damaged vehicles after an accident plays a significant role in damage assessment and collision trajectory analysis.This study employs a photogrammetric approach using an off-the-shelf mobile device and free Front Loader Drum Lifter software for the three-dimensional (3D) reconstruction of damaged vehicles to investigate traffic accidents.
In this study, the iPhone XS Max mobile phone camera was used for image acquisition of close-range photogrammetry and videogrammetry.After image capture, 3D models of forensic evidence were automatically reconstructed from the imagery using the COLMAP open-source software that provides user-friendliness to non-experts.The 3D models of the deformed vehicles were later used to analyze the damage and collision trajectory of a traffic accident.
The results showed that for Ski de fond - Homme - Sous-Vetements accuracy assessment of the 3D model test car, the values of root mean square error (RMSE) obtained from still images, video, and video with a stabilizer were 2.5, 3.1, and 2.
4 cm, respectively.The completeness of the generated 3D model obtained from still images provided greater clarity than videos with and without stabilizers, respectively.Therefore, the photogrammetric approach using a mobile device played a significant role in the 3D reconstruction of the forensic evidence used for traffic accident investigations, providing essential 3D information for court trial reports.