Abstract:To deal with the problem that the traditional phase-shifting (PS) method cannot be used to measure the three-dimension (3D) shape for a non-static object, a grating image projection-based method which combines the improved PS method with the Morlet wavelets is proposed. First, the phase of grating image is extracted by the Morlet complex wavelet ridge, the phase variation between image frames is estimated, and the calculation model of the phase-shifting method is modified according to the phase variation. Finally, the phase of the captured grating image is extracted using the modified calculation model, and the 3D shape of the non-static object is reconstructed. The root-mean-square (RMS) error of the proposed method is 0. 081 6 millimeter for a non-static measurement object in the field of view. The RMS error of the proposed method is 16. 92% and 44. 42% of the PS method and the single frame projection method, respectively, and is the smallest among the comparison methods. According to the measurement result, the proposed method expands the application scope of the PS method, and can measure the 3D shape for a non-static object accurately.