High-resolution low-noise 360-degree digital solid reconstruction using phase-stepping profilometry

Area of Science:

• Metrology
• Optical Engineering
• Computer Vision

Background:

• 360-degree profilometry enables full object digitization but faces challenges with data bandwidth and self-occluding shadows.
• Existing methods like spatial-carrier Fourier profilometry utilize only a fraction of the available data bandwidth.
• Intensity-based line detection algorithms are generally less accurate than phase-measuring techniques.

Purpose of the Study:

• To present a new experimental setup for 360-degree profilometry.
• To enable full phase-bandwidth phase-measuring algorithms for improved 3D digitization accuracy.
• To overcome limitations of existing 360-degree fringe-projection profilometers, specifically self-occluding shadows.

Main Methods:

• Development of a novel fringe-projection setup for 360-degree solids digitizing.
• Application of base-band, phase-stepping algorithms for full data phase-bandwidth utilization.
• Implementation of a simplified line-by-line data assembly within a shared cylindrical coordinate system.

Main Results:

• The proposed setup achieves high-resolution, low-noise 3D surface digitization of solids with diffuse surfaces.
• The base-band phase-stepping approach provides full data phase-bandwidth, outperforming band-pass methods.
• The new fringe-projection geometry effectively eliminates self-occluding shadows for convex objects.

Conclusions:

• The developed 360-degree profilometer offers superior accuracy and data bandwidth for 3D surface measurement.
• The system's design simplifies data assembly and avoids common issues like self-occluding shadows.
• Scalability for higher resolution and reduced noise is achievable by increasing angular resolution and phase steps.