Multiple Fisheye Camera Calibration and Stereo Measurement Methods for Uniform Distance Errors throughout Imaging Ranges

Abstract

This paper proposes calibration and stereo measurement methods that enable accurate distance and uniform distribution of the distance error throughout imaging ranges. In stereo measurement using two fisheye cameras, the distance error varies greatly depending on the measurement direction. To reduce the distance error, the proposed method introduces an effectual baseline weight into the stereo measurement using three or more fisheye cameras and their calibration. Accurate distance is obtained because this effectual baseline weight is the optimum weight in the maximum likelihood estimation. Experimental results show that the proposed methods can obtain an accurate distance with a 94% reduction in error and make the distribution of the distance error uniform.