Fig. 1. Schematic diagram of the modified height-phase function

Fig. 2. SPI-SFD imaging system based on high sensitivity lock-in photon counting detection technology. (a) Schematic diagram of the imaging system; (b) projection direction of the sinusoidal fringe; (c) sampling template

Fig. 3. Measurement results of the phantom profile of different height plates. (a) 3D reconstruction result of the modified height-phase function; (b) heights of the phantom surface reconstructed by different functions

Fig. 4. Profile measurement results of the hemisphere phantom. (a) Reconstruction heights under different sampling radius; (b) three-dimensional profile reconstruction results when r=6

Fig. 5. Measurement results of the optical characteristics of the double hemisphere phantom. (a) Absorption coefficient and reduced scattering coefficient before and after correction; (b) profile of the absorption coefficient; (c) profile of the reduced scattering coefficient

Fig. 6. Measurement results of the optical characteristics of the palm. (a) Collection area; (b) three-dimensional topography; (c) optical characteristics at different wavelengths before and after correction