A video-based stereoscopic imaging and measurement system (SIMS) for undersea applications

A PC-based stereoscopic imaging and measurement system (SIMS) was developed for undersea applications. The SIMS is capable of real-time image capture, recording and stereoscopic display as well as on-fine/on-demand 3-D measurement. The SIMS consists of a pair of underwater cameras, a controller, a pair of digital video recorders (DVRs), a PC to house the CPU, DVRs, hard drives, and other peripherals, and an autostereoscopic display. The cameras can be either mounted on a remotely operated vehicle (ROV) or carried by a diver to capture underwater scenes. Stereoscopic images are viewed on the glasses-free autostereoscopic display. Software modules were developed and/or adopted from published computer codes to operate the SIMS. Operations include those described above, camera calibration, and on-line/on-demand 3D measurement of features on the target objects. A virtual 3D camera calibration scheme was extended from a camera calibration method which captures the images of a coplanar checkerboard at several perspectives. The performance of the SIMS prototype for 3D measurement was evaluated by comparing the measured and actual distances between the checker corners on the checkerboard and between markers painted on a fish silhouette at several angles of orientation.