Optimization problem is to find the best solution from all feasible solutions such as camera calibration[1], 3D reconstruction [2], visual odometry[3], human skeleton modeling. In order to find best solution, choosing an object function is very important. According to object function, the optimization problem could be distinguished with singular or multiple variable problem and linear or nonlinear optimization problem. If the optimization problem has special constraints except an object function, the problem is constrained optimization problem in contrast non-constrained optimization problem.