Generalized phase unwrapping method that avoids jump errors for fringe projection profilometry.

Area of Science:

• Optical Metrology
• 3D Imaging
• Computer Vision

Background:

• Fringe projection profilometry (FPP) is a key 3D measurement technique.
• Jump errors, caused by wrapped phase and fringe order misalignment, limit FPP accuracy.
• Existing methods often compensate for errors rather than preventing them.

Purpose of the Study:

• To propose a novel phase unwrapping method for FPP that inherently avoids jump errors.
• To enhance the accuracy and reliability of 3D measurements in FPP systems.
• To provide a generalizable solution applicable to various fringe order recovery methods.

Main Methods:

• A generalized tripartite phase unwrapping (Tri-PU) method is developed.
• Two staggered wrapped phases are constructed from the original wrapped phase.
• Each fringe order period is divided into three distinct segments.

Main Results:

• The Tri-PU method effectively prevents jump errors, unlike compensatory approaches.
• Experimental validation confirms the method's effectiveness and generality.
• The technique demonstrates superior performance in measuring objects with sharp edges.

Conclusions:

• The proposed Tri-PU method offers a robust solution for phase unwrapping in FPP.
• It simplifies implementation while improving measurement accuracy, especially for complex geometries.
• This advancement contributes to more reliable and precise 3D surface reconstruction.