Fig. 1. Camera imaging model

Fig. 2. Flowchart of AEKF algorithm

Fig. 3. Virtual checkerboard targets

Fig. 4. Checkerboard target

Fig. 5. Schematic diagram of reprojection error

Fig. 6. Results of reprojection points for different algorithms

Fig. 7. Reprojection error of feature points

Fig. 8. Variation of reprojection error during iteration

Fig. 9. Reprojection error varying with noise level

Fig. 10. Reprojection error of calibration optimization algorithm at different Rk

Fig. 11. Variation of reprojection error during iteration

Fig. 12. Relationship between reprojection error and noise level

Fig. 13. Relationship between relative error of intrinsic and extrinsic parameters and noise level. Optimization of translation vector by using (a) UKF,(b) EKF, and (c) AEKF; optimization of scale factor by using (d) UKF, (e) EKF, and (f) AEKF; optimization of principal point coordinate by using (g) UKF, (h) EKF, and (i) AEKF