A composite fringe phase shift phase demodulation method, device and related medium

CN117419661BActive Publication Date: 2026-05-19SHENZHEN UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
SHENZHEN UNIV
Filing Date
2023-08-22
Publication Date
2026-05-19

AI Technical Summary

Technical Problem

Existing fringe projection techniques employ both time-phase unwrapping methods and spatial-phase unwrapping methods, which are inefficient and inaccurate, failing to meet the requirements of both high efficiency and high precision in most situations.

Method used

By combining phase shifting and cosine functions to generate fringe patterns containing two frequency components, and using the dual-frequency heterodyne principle for phase expansion, the projection of additional Gray code patterns and the second set of frequency fringe patterns is reduced, enabling independent calculation of each pixel.

Benefits of technology

It improves measurement efficiency and accuracy, expands the scope of application, and meets the industrial demand for both high efficiency and high precision in measurement.

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Abstract

The application discloses a composite fringe phase-shifting phase demodulation method and device and a storage medium, and the method comprises the following steps: combining a phase-shifting method and a cosine function to generate a group of fringe patterns; wherein the fringe patterns contain two frequency components; projecting a measured object based on the fringe patterns and collecting a projection image; calculating two groups of phases from the projection image, and unfolding the two groups of phases according to a double-frequency heterodyne principle to obtain a phase unfolding result. The two groups of fringe patterns of the double-frequency heterodyne are combined into one group, two groups of phases are obtained through mathematical principles, an additional projection of a gray code pattern or a fringe pattern of a second group of frequencies is not needed, the number of projection patterns and the number of collected fringe patterns are greatly reduced, the phases of all pixel points are independently calculated, error accumulation is avoided, the efficiency is greatly improved while a certain precision is ensured, and the purpose of quickly and completely and accurately obtaining a phase unfolding result is achieved.
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