Fig. 1. Diagram of novel directional target structure

Fig. 2. Flow chart of decoding process of new directional target

Fig. 3. Calibration model of binocular camera

Fig. 4. Diagram of zenith and azimuth angles

Fig. 5. Flow chart of proposed method

Fig. 6. Comparison between 25 sets of intrinsic parameters calculated by proposed method and those calculated by Zhang’s method. (a) f_x,l and f_y,l; (b) f_x,r and f_y,r; (c) u_0,l and v_0,l; (d) u_0,r and v_0,r

Fig. 7. Comparison between 25 sets of extrinsic parameters calculated by proposed method and those calculated by Zhang’s method. (a) r_x, r_y, r_z; (b) t_x, t_y, t_z

Fig. 8. Distributions of normal vectors of target at different positions. (a) Calibration image selected by proposed method; (b) calibration image used in Zhang’s method

Fig. 9. Comparison between errors obtained by proposed method and those obtained by Zhang's method. (a) Mean absolute reprojection error; (b) mean absolute collinearity error; (c) mean absolute coplanarity error; (d) mean absolute standard-length error

Fig. 10. Binocular calibration experiment based on local target information. (a) 17 left calibration images; (b) 17 right calibration images

Fig. 11. Comparison between 25 groups of binocular camera parameters calculated in additional experiments and those calculated by proposed method in section 4.1. (a)(b) Comparison of intrinsic parameters; (c)(d) comparison of extrinsic parameters

Fig. 12. Comparison between 25 groups of mean absolute errors obtained in additional experiments and those obtained by proposed method in section 4.1. (a) Mean absolute reprojection error; (b) mean absolute collinearity error; (c) mean absolute coplanarity error; (d) mean absolute standard-length error

Fig. 13. Comparison of results of measurement experiments

Table 1. Comparison of SD of intrinsic parameters of binocular camera obtained by proposed method and Zhang's method

Table 2. Comparison of SD of extrinsic parameters of binocular camera obtained by proposed method and Zhang’s method