3D reconstruction with single-frame two-step phase-shift method based on orthogonal composite fringe pattern projection

In order to realize single-frame three-dimensional (3D) reconstruction, a single-frame two-step phase-shift method based on orthogonal composite pattern projection is proposed to solve the problem that the traditional N-step phase-shift profilometry needs multiple projections for 3D reconstruction. The orthogonal composite pattern uses only two carrier channels to reduce the spectrum overlapping influence on the demodulation accuracy of carrier and modulated fringes. A two-dimensional variational mode decomposition (2DVMD) method is adopted to remove the background DC component of the sinusoidal fringe to overcome the mode overlap problem by controlling the size of the bandwidth. Thus, the two-step phase-shift method is applied to calculate the phases for 3D reconstruction. The experimental results show that, compared with the typical Fourier Transform Profilometry (FTP) method , 3-step composite method and 2+1 composite method, the 3D reconstruction accuracy of the proposed method is improved by 49.1% ,31.4% and 23.2% respectively according to Mean Absolute Error (MAE), and by 73.0%, 58.4% and 56.8% respectively according to Mean Squared Error (MSE) as the evaluation index. Finally, the dynamic 3D reconstruction experiment demonstrates the good adaptability of dynamic 3D reconstruction.