Fig. 1. Experimental system. (a) Experimental system model; (b) diagram of experimental system optical path

Fig. 2. Data processing flow chart of the proposed method

Fig. 3. Histogram of photon counting statistics. (a) Typical histogram of photon counting statistics for a specific single pixel; (b) photon counting statistics histogram after accumulation of all pixels within M×N

Fig. 4. 3D image reconstruction of the Bowling ball simulation scene at the average PPP of 2, SBR of 0.08, 0.04, 0.02, and 0.01 respectively. (a)-(l) 3D reconstruction images of the method in Ref.[24], the method in Ref.[28], and our proposed method under different SBR; (m) (n) Bowling ball picture and the real depth value

Fig. 5. Performance evaluation of depth estimation and computation time on the Bowling simulation dataset under different algorithms, the average PPP is 2. (a) RMSE of depth estimation; (b) computation time comparison

Fig. 6. 3D image reconstruction of the building model at SBR of 0.05 and PPP of 2.35. (a) Target picture; (b) depth estimation result obtained by the method in Ref.[24]; (c) depth estimation image obtained by the method in Ref.[28]; (d) depth estimation image obtained by our proposed method; (e) ground truth