Method for detecting and correcting unpacking phase error based on phase distribution

Abstract

The invention discloses a method for detecting and correcting an unpacking phase error based on phase distribution, and the method is suitable for obtaining the phase when phase unpacking is carried out by adopting an information assistance method. The method mainly comprises the following steps of setting a threshold based on the gradient distribution of an unpacking phase, and obtaining a phasediagram edge; determining all points in which unpacking phase errors may exist by the detected phase diagram edge and a region enclosed by a closed edge; and performing error correction on these points, and obtaining the correct phase distribution. According to the method of the invention, due to the fact that two processes of phase error detection and correction are separated, effective labelingof phase discontinuous regions is also realized in the phase error detection, so that there is no need to use mass chart guidance to avoid the discontinuous regions during phase correction, and the method has robustness and efficiency.

Description

technical field [0001] The invention belongs to the technical field of optical three-dimensional measurement, in particular to an unwrapping phase error detection and correction method based on phase distribution. Background technique [0002] Fringe projection profilometry is a three-dimensional measurement method with fast measurement speed, good environmental adaptability and high precision. It is not only widely demanded in manufacturing inspection, but also has broad application prospects in robot vision, pattern recognition, virtual reality and other fields. The phase of the sampled fringe image is the core parameter for 3D reconstruction by fringe projection profilometry, and its accuracy directly determines the accuracy of 3D measurement. The main links that affect the accuracy of the phase solution are phase demodulation and phase unwrapping. The phase unwrapping is the process of restoring the true value of the demodulated phase wrapped in [-π, π). There are many ...

AI Technical Summary

Problems solved by technology

The method proposed by Feng Shijie et al. cannot detect large areas of points with unwrapped phase errors. In addition, it may misjudgment some mis-smoothed points, and the detected error points are not corrected.

The method proposed by Yi Ding et al. is also unable to detect large areas of points with unwrapped phase errors, and when there is a large surface discontinuity across the field of view, misjudgment of the phase of the nearby area may occur, which in turn leads to miscorrection of phase

The method proposed by Dong-ukKam et al. has similar shortcomings to the method proposed by Feng Shijie et al. In addition, it needs to calculate the mean square error of the phase, the second norm and other parameters point by point in the specific use process, and it is difficult to quickly correct the phase error.

The phase unwrapping error correction method proposed by Zhang Chunwei et al. does not separate the detection and correction process of the phase error. Guided by graphics, the efficiency is low, and it is not conducive to the automatic realization of the whole process

Images