Fig. 1. Schematic diagram of the NLOS imaging method using a TOF camera.

Fig. 2. Untreated NLOS images acquired under coupled scattering characteristics and their formation mechanisms.

Fig. 3. NLOS scattered light propagation and imaging under different object and relay surface scattering characteristics.

Fig. 4. Light intensity distribution of object light information on the detector in scenes with different scattering characteristics.

Fig. 5. Reconstruction method for scattered images based on the SSM model.

Fig. 6. Imaging system setup and measured objects. (a) Optical platform scenario. (b) Optical platform scene dimensions. (c) Corridor scenario using door as relay surface. (d) Corridor scenario using white wall as relay surface. (e) Photos of objects.

Fig. 7. Schematic diagrams of the distributions of the scattering characteristics of the two materials. (a) Method for measuring the scattering distribution. (b) Photo of the material. (c) Approximate measurement results of the scattering distributions of two non-Lambertian materials; PP board is on top, and PMMA board is below.

Fig. 8. Reconstruction results with the plastic plate and acrylic plate as relay surfaces. (a) Raw data collected from the surface of PP plate and acrylic plate. (b) Reconstructed data by the SSM model. (c) Ground truth. (d), (e) MSEs and PSNRs of all data in the test set.

Fig. 9. Reconstruction results on the basis of the Lambertian relay surface and plastic letters. (a) Raw data collected from the Lambertian surface. (b) Reconstructed data by the SSM model. (c) Ground truth.

Fig. 10. Reconstruction results of the Lambertian relay surface and plaster statue. (a) Raw data. (b) Reconstructed data by the SSM model. (c) Ground truth. (d) MSEs, PSNRs, and SSIMs of all data in the test set.

Fig. 11. NLOS imaging result of clothes in a corridor when the door and a white wall serve as relay surfaces. (a) Raw data collected from white wall and door. (b) Reconstructed data by the SSM model. (c) Ground truth. (d), (e) MSEs and PSNRs of all data in the test set.