Fig. 1. Schematic of camera pose variation based on PnP

Fig. 2. Dual-orthogonal-camera model

Fig. 3. Experimental results with varying number of control points. (a) Mean rotation error; (b) median rotation error; (c) standard rotation error; (d) mean translation error; (e) median translation error; (f) standard translation error

Fig. 4. Experimental results with increasing level of Gaussian noise. (a) Mean rotation error; (b) median rotation error; (c) standard rotation error; (d) mean translation error; (e) median translation error; (f) standard translation error

Fig. 5. Computational time of all the methods. (a) Result with control points changing from 4 to 100; (b) zoomed-in version of fig. 5 (a)

Fig. 6. Influence of installation error between two cameras on the accuracy of 6-DOF estimation. (a) Mean rotation error; (b) median rotation error; (c) mean translation error; (d) median translation error

Fig. 7. Experimental layout

Fig. 8. Calibration images in different fields of view. (a) Field of camera 0; (b) field of camera 1; (c) field of measuring camera

Fig. 9. Relative pose of three cameras. (a) Actual relative pose; (b) calibrated relative pose

Fig. 10. Mean and median errors of subsidence with regard to varying number of control points. (a) Mean error of subsidence; (b) zoomed-in version of fig.10(a); (c) median error of subsidence; (d) zoomed-in version of fig. 10(c)