Fast Distance Measurement Method by Parallel-Shift Arrangement Stereoscopic Camera

Abstract

Computation time of stereo matching process for distance measurement has been greatly reduced by parallel-shift optical arrangement stereoscopic camera from that of cross arrangement camera. This stereoscopic camera consists of two camera units which are combined in parallel. Image planes (CCD) of these camera units are motor-driven to shift then from its central position in order to change the location of camera axis crossing point. This optical arrangement eliminates keystone distortion and horopter becomes a vertical flat plane at the crossing point and epipolar lines of right and left images become fully corresponding horizontal lines. Therefore, matching process can be achieved only on one sweep line. This feature simplifies the matching algorithm and matching process can be faster than a conventional 2 dimensional correlation method. Computational cost for this stereo matching process is estimated more than 88% reduction to cross arrangement method.