Phase error compensation method applied to grating three-dimensional projection measurement

Abstract

The invention discloses a phase error compensation method applied to grating three-dimensional projection measurement. The method includes the following steps: generating sine grating stripes; collecting grating stripes that are modulated by the surface of an object; pre-processing images; carrying out phase unwrapping through a phase shift method on the basis of the pre-processed stripe images; projecting a grey-scale image with a single gray value onto the surface of a standard white board; mapping regional results in the step (5) onto a target surface of a projector through an obtained ideal phase; establishing regional correction models for different regions according to the regional results; projecting the sine grating stripes onto the object; solving an initial phase through a phaseshift method, compensating the phase on the basis of established regional error compensation, and solving an actual phase; and through calibrated camera parameters and a solved absolute phase, calculating three-dimensional coordinate information of a to-be-measured object through a spatial intersection method. The method overcomes phase errors and measurement errors caused by Gamma non-linearity.

Description

technical field [0001] The invention relates to the technical field of three-dimensional information reconstruction, in particular to a phase error compensation method applied in grating three-dimensional projection measurement. Background technique [0002] Phase measurement profilometry (PMP) is a three-dimensional measurement technology based on fringe projection and phase measurement. Due to its characteristics of non-contact, high speed, high precision, large data volume, large working distance and wide application range of materials, this kind of The technology has been widely used in industrial inspection, machine vision, reverse engineering and other fields. [0003] In the three-dimensional profile measurement based on the phase-shift fringe projection method based on phase recovery, the sinusoidal grating image projected by the projector on the surface of the object is captured by the camera, and the phase is calculated by using a phase shift algorithm of more than...

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is to provide a phase error compensation method applied in grating three-dimensional projection measurement. By establishing a sub-area error compensation model according to the phase error of the object to be measured and the Gamma value distribution law on the surface of the projector, it can be solved. Phase error and measurement error due to Gamma nonlinearity

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