Noise free defect detection in ceramic tableware using a portable digital holographic camera.

Area of Science:

• Materials Science
• Optical Metrology
• Non-Destructive Testing

Background:

• Ceramic tableware quality control is crucial.
• Existing crack detection methods may lack precision or portability.
• Surface defects can compromise product integrity and safety.

Purpose of the Study:

• To develop and validate a portable digital holographic camera system for crack detection in ceramic tableware.
• To apply digital image processing techniques for precise defect localization.
• To mitigate speckle noise in holographic interferometry for improved phase quality.

Main Methods:

• Utilizing double-exposure digital holographic interferometry with a portable digital holographic camera.
• Applying digital image processing to amplitude and phase information of reconstructed wavefronts.
• Implementing an averaging filter with optimized kernel size to reduce speckle noise in interferometric phase data.
• Analyzing the signal-to-noise ratio to evaluate the filter's effectiveness.

Main Results:

• Successfully detected cracks in ceramic tableware using the developed system.
• Minimized speckle noise through iterative averaging filter application.
• Validated the accuracy of crack size measurement (0.08 mm) with a mechanical profiler, achieving a 6.6% error rate.
• Demonstrated the correlation between averaging filter kernel size and interferometric phase quality.

Conclusions:

• The portable digital holographic camera system is effective for detecting cracks in ceramic tableware.
• Optimized digital image processing, particularly speckle noise reduction, is key to accurate defect detection.
• This technology has the potential to enhance quality control standards in the tableware industry.