Fig. 1. Underwater binocular measurement system. (a) Top view of internal structure; (b) seal outline drawing of equipment

Fig. 2. Binocular stereo vision model

Fig. 3. Flow chart of measurement system

Fig. 4. Line-structured light array

Fig. 5. Measurement model of underwater binocular system

Fig. 6. Underwater binocular system imaging

Fig. 7. Schematic of polar geometric constraints

Fig. 8. Intersection of external polar and light bar

Fig. 9. Comparison results of feature extraction. (a) Cylinder; (b) sheet metal parts; (c) cylindrical point cloud of proposed method; (d) cylindrical point cloud of image method; (e) point cloud of sheet metal parts of proposed method; (f) point cloud of sheet metal parts of image method

Fig. 10. Test results of laser stripe extraction. (a) Custom pattern; (b) extraction result of custom pattern; (c) left camera image of irregular metal plate; (d) extraction result of irregular metal plate; (e) left camera image of stone; (f) extraction result of stone

Fig. 11. Spherical point clouds obtained from one measurement

Fig. 12. Three-dimensional measurement of underwater sheet metal parts. (a) Experimental environment; (b) measured object; (c) three-dimensional point clouds

Fig. 13. Three-dimensional measurement of underwater rock. (a) Measured object; (b) three-dimensional point clouds