Paraxial 3D shape measurement using parallel single-pixel imaging.

Area of Science:

• Optics and Photonics
• Metrology
• Computer Vision

Background:

• Traditional 3D shape measurement methods like shape-from-defocus and projection-triangulation face challenges with sensitivity, signal-to-noise ratio, and phase detection.
• Fringe projection techniques with vertical scanning can reduce shadow and occlusion but have inherent limitations.
• Developing accurate and robust 3D shape measurement techniques remains crucial for various scientific and industrial applications.

Purpose of the Study:

• To propose and validate a novel paraxial 3D shape measurement method using parallel single-pixel imaging (PSI).
• To address the limitations of existing 3D measurement techniques, particularly in sensitivity and robustness.
• To achieve dense and accurate 3D reconstructions of objects with diverse materials and textures.

Main Methods:

• Utilizing parallel single-pixel imaging (PSI) for 3D shape measurement.
• Encoding depth information in the radial distance to the projector optical center, determined by light transport coefficients (LTCs).
• Employing third-order polynomial fitting for precise depth mapping and system calibration.

Main Results:

• Demonstrated robust and dense 3D shape reconstruction using the proposed PSI method.
• Achieved a depth accuracy of 20 micrometers (μm) in experimental measurements.
• Obtained a root-mean-square error (RMSE) of plane fitting up to 43 μm, validating accuracy on various objects.

Conclusions:

• The proposed paraxial 3D shape measurement using PSI offers a robust and accurate alternative to conventional methods.
• The technique successfully reconstructs dense 3D shapes with high precision, suitable for objects with different properties.
• Experimental validation confirms the method's capability to achieve micrometer-level depth accuracy.