A gamma nonlinear correction method and system for phase measurement profilometry

Abstract

The invention belongs to the optical three-dimensional digital imaging technology field and provides a gamma non-linear correction method of a phase measurement profilometry and a system thereof. In the invention, a classic least square phase displacement phase unwrapping method and a gamma model of a projection-imaging apparatus are combined, a general phase error distribution model of a phase measurement profilometry measurement system is derived and then based on the phase error distribution model, the high-efficiency, high-precision and high-robustness gamma non-linear correction method and the system are provided. The method and the system are good for further deep theory derivation and system error analysis and are suitable for a phase shift method with any step number and a corresponding measurement requirement. The method and the system satisfy a requirement of high-speed, high-precision and high-universality three-dimensional digital imaging and measurement based on the phase measurement profilometry.

Description

technical field [0001] The invention belongs to the technical field of optical three-dimensional digital imaging, in particular to a gamma nonlinear correction method and system of digital fringe projection phase measurement profilometry. Background technique [0002] Phase measurement profilometry is a non-contact, full-field measurement optical three-dimensional digital imaging and measurement method. This method uses a projection device to project a group of sinusoidal gratings or quasi-sine gratings onto the object surface, uses an imaging device to collect the fringe pattern modulated by the surface shape of the object, and uses phase shift technology to calculate the spatial phase value of each measurement point, and then uses the phase - Depth Mapping calculates the depth information of the surface of the object. Phase measurement profilometry has been widely used due to its high imaging density, high imaging speed, high measurement accuracy and high measurement univ...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the embodiments of the present invention is to provide a gamma nonlinear correction method for phase measurement profilometry, which aims to solve the problem that the existing phase error compensation or gamma correction method is limited to a specific step number phase shift method and is limited to a specific phase measurement Profilometry measurement system does not have the problem of universality

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