Fig. 1. Schematic of database establishment

Fig. 2. Experimental device

Fig. 3. Object images and depth images of target with different attitudes. (a) (b)-60°; (c) (d) -40°; (e) (f) -20°; (g) (h) 0°; (i) (j) 20°; (k) (l) 40°

Fig. 4. Images of the target and its single-photon counting three-dimensional images (depth images) at different photon counts. (a)-(d) Image of the target at -45° attitude and the depth images at 10, 50, and 100 photon counts respectively; (e)-(h) image of the target at 25° attitude and the depth images at 10, 50, and 100 photon counts respectively

Fig. 5. Correlation coefficient between the single-photon counting 3D imaging image (depth image) of the actual attitude of the target and the different attitude depth images in the database. (a) Correlation coefficient between the target depth images and depth images at different attitudes in the database; (b) correlation coefficient between the target depth images under 10, 50, and 100 photon counts and target depth image at the estimated attitude

Fig. 6. Object maps and depth maps of target under different attitudes. (a) (0°, 0°),(20°, 0°),(40°, 0°) attitude; (b) (0°, 15°),(20°, 15°),(40°, 15°) attitude; (c) (0°, 30°),(20°, 30°),(40°, 30°) attitude

Fig. 7. Images of the target and its single-photon counting three-dimensional images (depth images) at (15°, 35°) attitude under different SBR. (a)(e) SBR is 8.13, the target and its depth image; (b)(f) SBR is 4.83, the target and its depth image; (c)(g) SBR is 3.21, the target and its depth image; (d)(h) SBR is 0.72, the target and its depth image; (i) correlation coefficient between the depth images in the database and the actual depth image of the target under different SBR

Fig. 8. Images of the target and its single-photon counting three-dimensional images (depth images) at different attitudes. (a) (d) -30°; (b) (e) 0°; (c) (f) 30°

Fig. 9. Images of the target and its single-photon counting three-dimensional images (depth images). (a)(b) Target and its depth image at 20° attitude; (c)(d) target and its depth image at -20° attitude; (e) correlation coefficient between the actual attitude depth image of the target and the depth image in the database