Fig. 1. Schematic of the experimental system

Fig. 2. Simulation results of HDR-SW method. (a) θs0, m0, and m; (b) d0' and m0; (c) d' and m; (d) θs0, m0, and m; (e) errors of dHDR‑SW' and dHDR‑SW; (f) calculation error of linear regression method; (g) calculation error of low-precision solution of proposed method; (h) calculation error of high-precision solution of proposed method; (i) Y-axis of Fig. 2(h) is enlarged

Fig. 3. Experimental results of a step calibration block. (a) Wrapped phase θs0; (b) m0; (c) m; (d) surface profile imaging

Fig. 4. Surface profile imaging results. Results of a coin with (a) proposed method and (b) FFT; (c) comparison of the line profile distribution; (d) result of a cellphone circuit board, and the inset is photograph of the sample