J4 ›› 2013, Vol. 40 ›› Issue (2): 1-4+42.doi: 10.3969/j.issn.1001-2400.2013.02.001

• Original Articles •     Next Articles

Rank-1 constraint for camera calibration based on spheres

JIA Jing1,2;WU Chengke2   

  1. (1. School of Mechano-electronic Engineering, Xidian Univ., Xi'an  710071, China;
    2. State Key Lab. of Integrated Service Networks, Xidian Univ., Xi'an  710071, China)
  • Received:2012-05-30 Online:2013-04-20 Published:2013-05-22
  • Contact: JIA Jing E-mail:jjia@mail.xidian.edu.cn
  • About author:

Abstract:

With the rank-1 constraint, a method for camera intrinsic parameters calculation based on spheres is proposed. The geometric interpretation of the rank-1 constraint is explored from the relation of the image of the absolute conic and the sphere image. Three algebraic equations are derived from the rank-1 constraint. The relation of the sphere images and the camera intrinsic parameters is clearly interpreted in vision geometry. Finally, a nonlinear optimized method is used with the three constraint equations for improving the accuracy. Experimental results show that our method is robust. Compared with the traditional method, it can improve the accuracy of the results of the intrinsic parameters.

Key words: camera calibration, sphere, rank-1 constraint, geometry interpretation