Camera calibration technology based on circular points for binocular stereovision system

Abstract

Based on analyzing and partially testing the current methods for camera calibration in computer vision, inspired by Zhang's technique, we introduced a new method for binocular stereovision camera calibration. In this method, a planar object with a series of circles was used as calibration template, and the centers of circles were regarded as control points. The proposed method requires the two cameras with relatively fixed position to simultaneously observe the calibration template at a few (at least two) different orientations by moving the cameras or planar object freely, then extracts the centers' coordinates of circles or ellipses by image processing technique. On this basis, calculate every camera' intrinsic and extrinsic parameters, then calculate the position parameters of the two cameras. The main point of this method is that it can match the points in the model plane and their image points easily; compared with Zhang's calibration methods, it can reduce the errors of extracting control points. Experimental results and contrast tests show proposed method is accurate and very applicative to camera calibration of binocular stereovision system. © 2011 Springer-Verlag.