There are numerous ways to use video cameras to measure 3D dynamic spatial displacements. When the scene geometry is unknown and the motion is unconstrained, two calibrated cameras are required. The data from both scenes are combined to perform the measurements using well known stereoscopic techniques. There are occasions where the measurement system can be simplified considerably while still providing a calibrated spatial measurement of a complex dynamic scene. For instance, if the sizes of objects in the scene are known a priori, these data may be used to provide scene specific spatial metrics to compute calibration coefficients. With this information, it is not necessary to calibrate the camera before use, nor is it necessary to precisely know the geometry between the camera and the scene. Field-ofview coverage and sufficient spatial and temporal resolution are the main camera requirements. Further simplification may be made if the 3D displacements of interest are small or constrained enough to allow for an accurate 2D projection of the spatial variables of interest. With proper camera orientation and scene marking, the apparent pixel movements can be expressed as a linear combination of the underlying spatial variables of interest. In many cases, a single camera may be used to perform complex 3D dynamic scene measurements. This paper will explain and illustrate a technique for using a single uncalibrated video camera to measure the 3D displacement of the end of a constrained rigid body subject to a perturbation.

Date Published: 5 September 2014
PDF: 9 pages
Proc. SPIE 9202, Photonics Applications for Aviation, Aerospace, Commercial, and Harsh Environments V, 92021L (5 September 2014); doi: 10.1117/12.2064069

Published in SPIE Proceedings Vol. 9202:
Photonics Applications for Aviation, Aerospace, Commercial, and Harsh Environments V
Alex A. Kazemi; Bernard C. Kress; Edgar A. Mendoza, Editor(s)