Camera parameter estimation apparatus, camera parameter estimation method, and computer-readable recording medium

A camera parameter estimation method of estimating camera parameters when an object is photographed by a camera, the camera parameter estimation method comprising:

• (a) dividing an error function representing a transformation between at least six sets of three-dimensional points relating to the object and two-dimensional points on an image that correspond to the respective three-dimensional points into a plurality of subproblems based on dependency among the camera parameters and the flatness of distribution of the three-dimensional points, and calculating optimal solution candidates in the respective plurality of subproblems;
• and
• (b) with the optimal solution candidates as initial values, finding an optimal solution for minimizing an error obtained by the error function, and outputting the found optimal solution as an optimal camera parameter.

A non-transitory computer-readable recording medium that includes a program recorded thereon for, with a computer, estimating camera parameters when an object is photographed by a camera, the program including instructions that cause the computer to carry out:

• (a) dividing an error function representing a transformation between at least six sets of three-dimensional points relating to the object and two-dimensional points on an image that correspond to the respective three-dimensional points into a plurality of subproblems based on dependency among the camera parameters and the flatness of distribution of the three-dimensional points, and calculating optimal solution candidates in the respective plurality of subproblems;
• and
• (b) with the optimal solution candidates as initial values, finding an optimal solution for minimizing an error obtained by the error function, and outputting the found optimal solution as an optimal camera parameter.