An Adaptive Brightness Global Digital Image Correlation Method for Deformation Measurement Using Overexposed Images

Area of Science:

• Materials Science
• Optical Engineering
• Mechanical Engineering

Background:

• Overexposed images from welding or metal reflection hinder accurate deformation measurements.
• Existing methods struggle with the high reflectivity and dynamic nature of welding processes.
• Tracking surface deformation is critical for understanding and optimizing manufacturing processes.

Purpose of the Study:

• To develop a robust method for deformation measurement using overexposed images.
• To improve the accuracy and reliability of digital image correlation in challenging industrial settings.
• To enable dynamic deformation measurement during welding for process optimization.

Main Methods:

• An Adaptive Brightness Global Digital Image Correlation (AB-GDIC) method is proposed.
• Image overexposure is managed using an improved Dark Channel Prior method for brightness adjustment.
• Finite Element Partitioning is integrated for enhanced deformation analysis.

Main Results:

• The improved dark channel method effectively adjusts image brightness without distorting distribution.
• A significant increase in Mean Intensity Gradient was observed in modified image partitions.
• The method successfully enabled dynamic measurement of weld deformation from overexposed images.

Conclusions:

• The AB-GDIC method overcomes limitations in measuring deformation from overexposed welding images.
• Accurate dynamic deformation tracking, including unstable and angular deformation, is achievable.
• The findings support optimizing welding processes through detailed deformation analysis.