Correcting projector lens distortion in real time with a scale-offset model for structured light illumination

Area of Science:

• Optical Engineering
• Metrology
• Computer Vision

Background:

• Fringe projection profilometry is crucial for 3D reconstruction.
• Lens distortion in projectors degrades phase accuracy and 3D point cloud quality.
• Existing methods for projector lens distortion are either time-consuming or unsuitable for binary fringe patterns.

Purpose of the Study:

• To develop a real-time phase correction method for projector lens distortion.
• To improve the accuracy and computational speed of 3D point cloud generation.
• To address limitations of existing post-undistortion and pre-distortion techniques.

Main Methods:

• A scale-offset model was developed to characterize projector distortion with four correction parameters.
• The model enables fast post-undistortion using look-up tables.
• The method was validated through experimental measurements.

Main Results:

• The proposed method suppressed distortion error by a factor of 20×.
• Root mean square error was reduced to less than 45 µm/0.7‰.
• Computation speed was improved by a factor of 50× compared to iterative methods.

Conclusions:

• The scale-offset model offers an effective and efficient solution for real-time projector lens distortion correction.
• This advancement enhances the quality and speed of 3D reconstruction in fringe projection profilometry.
• The method provides a practical alternative to existing, less efficient techniques.