Adaptive main frequency bandpass filters used in Fourier transform profilometry

The basic principle of Fourier Transform Profilometry(FTP) is introduced, then a new Adaptive Main Frequency Bandpass Filter(A-MFBF) algorithm is proposed based on the simulation result of phase modulation frequency spectrum. The proposed algorithm is used to design the A-MFBF to filter out the main frequency and reconstruct the phase of a measured object. Results show that the precision of 3-D measurement system can be improved by 5% relative to that of the average ones, and its metrical precision can be repeated steadily. The real-time 3-D shape reconstruction is implemented by proposed A-MFBF without effect by subjective factors. Furthermore, a experiment of reconstructing phase for the steel with ribs is carried out, and the precision of reconstructed measurement is calculated and analyzed. The results show that the precision from the theoretical simulation is in good agreement with the experimental results, which demonstrates the validity of the algorithm.