Automatic fringe detection algorithm used for moire deflectometry

Area of Science:

• Optics and Photonics
• Image Processing
• Metrology

Background:

• Moire deflectometry is a technique used for optical testing and metrology.
• Accurate fringe detection is crucial for quantitative analysis in moire deflectometry.
• Existing fringe detection methods can be sensitive to noise and deformations.

Purpose of the Study:

• To develop an automatic fringe detection algorithm for moire deflectometry.
• To create a dynamic algorithm capable of tracking deforming moire fringes.
• To enable precise measurement of fringe patterns for optical analysis.

Main Methods:

• A novel algorithm based on a linked set of points, mimicking a "rubber band" behavior.
• Points are attracted to moire fringes, achieving regular spacing along the fringe pattern.
• The algorithm dynamically tracks fringe deformations in real-time.

Main Results:

• The algorithm successfully identifies and aligns points with moire fringes.
• It accurately determines fringe coordinates even under continuous deformation.
• The distance of adapted points to a reference line is calculated, fulfilling deflectometry requirements.

Conclusions:

• The proposed automatic fringe detection algorithm is effective for moire deflectometry.
• Its dynamic nature allows for tracking complex and deforming fringe patterns.
• This method enhances the precision and robustness of optical metrology using moire techniques.