Precise 3D measurements for tracked objects from synchronized stereo-video sequences

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), Volume 8888, 2014, Pages 757-769© Springer International Publishing Switzerland 2014. This paper presents a system suitable to perform precise and fast 3D measurements from synchronized stereo-video sequences and provide target’s georeference in a known reference system. To this direction we combine a robust tracker with photogrammetric techniques into a fast and reliable system. For tracking objects and people, we adopt and modify a stable human tracker able to cope efficiently with the trade-off between model stability and adaptability. For achieving accurate and precise 3D measurements, camera calibration was implemented in order to recover the intrinsic parameters of the cameras of the configuration. Finally, for precise and reliable calculation of the 3D trajectory of the moving person, we apply bundle adjustment for all frames. Bundle adjustment is a very accurate algorithm and has the advantages of being tolerant of missing data while providing a true Maximum Likelihood estimate. The results have been tested and evaluated in real life conditions for proving the robustness and the accuracy of the system