Proceedings Article | 15 April 1994
Proc. SPIE. 2177, Stereoscopic Displays and Virtual Reality Systems
KEYWORDS: Particles, 3D modeling, Image processing, Visualization, 3D displays, 3D image processing, Cameras, Image acquisition, Photography, Stereoscopic displays
A stereoscopic system was developed that integrates hardware and software components for image acquisition, digitization, processing, display, and measurements. The model-induced trajectories of nearly neutrally buoyant fluorescent particles, illuminated with a 15-W pulsed copper vapor laser, are tracked in a towing tank by stereoscopic time-lapse photography using two 35-mm cameras positioned at a 90-degree angle from the top and the side. A C program, HI, drives two data I/O boards hosted in a PC to set up the run parameters, control the operations of the laser and camera shutters, and acquire the stereo images. The photographic records are digitized and processed to derive the centroids of reference marks and particle images. The centroids are then fed into a Windows-based program, Track/3D, to perform image correlation, correction for image distortion, stereo conversion, stereoscopic display, and measurements. The display module incorporates a graphics library that drives a stereoscopic display adapter attached to a monitor; the stereogram must be viewed with polarizing glasses. Functions are available for image translation, rotation, zooming, and on- screen measurements. The velocity and acceleration components of the 3-D flow field induced by the model are derived from the trajectories, serving as a basis for whole-field stereoscopic quantitative flow visualization.
