Fig. 1. Schematic diagram of modulation measurement profilometry based on phase-shifting and focal-switching method

Fig. 2. Schematic diagram of measurement system

Fig. 3. Relationship between height distribution and serial number corresponding to maximum modulation value at pixel (400, 500)

Fig. 4. Error distribution between tested plane and fitted ideal plane. (a) Error distribution of first tested plane obtained by TS-PSM; (b) error distribution of first tested plane obtained by PM; (c) error distribution of second tested plane obtained by TS-PSM; (d) error distribution of second tested plane obtained by PM

Fig. 5. Error distribution between tested ball and standard ball. (a) Error distribution of first tested ball obtained by TS-PSM; (b) error distribution of first tested ball obtained by PM; (c) error distribution of second tested ball obtained by TS-PSM; (d) error distribution of second tested ball obtained by PM

Fig. 6. Measured object. (a) Measured object with protruding letter "TURN" on surface; (b) fringe pattern when S(O₁,x,y)=100; (c) fringe pattern when S(O₁,x,y)=150; (d) fringe pattern when S(O₁,x,y)=200

Fig. 7. Comparison of modulation curves obtained by two methods at different locations. (a) Left point marked in Fig. 6(b); (b) middle point marked in Fig. 6(b); (c) right point marked in Fig. 6(b)

Fig. 8. Experimental results. (a) Reconstruction result obtained by TS-PSM; (b) reconstruction result obtained by PM; (c) profile comparison

Fig. 9. Comparison of reconstruction results. (a) Measured object with protruding letter "PUSH" on surface; (b) fringe pattern when S(O₂,x,y)=150; (c) reconstruction result obtained by TS-PSM; (d) reconstruction result obtained by PM; (e) profile comparison