Modal-based camera correction for large pitch stereo imaging

Abstract

Stereo imaging is typically performed using two cameras that have been calibrated to account for lens-induced distortion and pointing errors, resulting in rectified images that are processed to obtain distance information. The accuracy of a 3-D map obtained from stereopsis is closely tied to the calibration data, and so relative motion between the cameras must be kept small. In order to reduce errors from a stereo image caused by motion, the structural connection between the cameras can be stiffened, but this comes with a weight and size penalty. For cameras that have a large baseline (pitch) distance, it may be impossible to have enough stiffness in the structure to obtain reasonable error bounds. An alternative approach is to model the camera motion using a modal technique and account for this motion during imaging. This paper outlines a procedure for stereo camera correction using measured accelerations to optimally trigger the camera. Results of the technique are shown for a simple beam that is center-mounted to a shaker to induce symmetric bending. ©2010 Society for Experimental Mechanics Inc.