Optimal fringe angle selection for digital fringe projection technique

Area of Science:

• Optical Metrology
• 3D Imaging and Reconstruction

Background:

• Digital fringe projection (DFP) systems commonly employ horizontal or vertical fringe patterns for 3D shape measurement.
• These standard fringe orientations may not always provide the largest phase change for a given depth variation, potentially limiting measurement accuracy.

Purpose of the Study:

• To investigate the limitations of conventional fringe orientations in DFP systems.
• To propose and validate a novel method for determining the optimal fringe angle to maximize phase change and improve 3D shape measurement accuracy.

Main Methods:

• A set of horizontal and vertical fringe patterns were projected onto a step-height object.
• The resulting phase maps from these projections were analyzed to determine the optimal fringe angle.

Main Results:

• The study confirmed that specific fringe angles, other than purely horizontal or vertical, yield a larger phase change in response to depth variations.
• The proposed method successfully identified an optimal fringe angle for the tested object.

Conclusions:

• The optimal fringe angle can significantly enhance the sensitivity of DFP systems to depth variations.
• The developed method provides an efficient approach for determining this optimal angle, improving the precision of 3D shape measurement.