Denoising method for shape measurement based on three wavelength phase shift profilometry
In order to reduce noise points in shape measurement of 3D objects using Phase Shift Profilometry (PSP) methods, a novel Three Wave Length PSP (TWPSP) method was investigated. Firstly, relevant problems of equivalent wavelength and unwrapped phase were analyzed. Then, the solution of unwrapping method for TWPSP was derived. Finally, global phase filtering based method was used to reduce the phase noises. The measurement system was designed to measure the calibration target as well as the complicated shape target. Experimental results show that the noisy points of three-dimensional graphics are reduced by 98.02%, and the speed of 3D reconstruction is raised by 12%. The experiment and analysis results show that this system has better robust and higher measurement accuracy, thus the noises in the shape measurement can be suppressed significantly.