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Defect inspection for underwater structures based on line-structured light and binocular vision.
Applied Optics
|October 6, 2021
Summary
This study introduces a two-stage structured light imaging method for accurate underwater surface defect detection. The technique enhances inspection accuracy beyond passive vision methods, proving effective for structural integrity assessments.
Area of Science:
- Engineering
- Computer Vision
- Robotics
Background:
- Underwater structure inspection is critical for safety and maintenance.
- Passive vision methods lack the required accuracy for detailed surface defect analysis.
- Accurate defect detection is essential for preventing structural failures.
Purpose of the Study:
- To develop a more accurate method for underwater surface defect inspection.
- To improve the reliability of defect detection using structured light imaging.
- To enable precise localization and measurement of surface defects.
Main Methods:
- A two-stage approach utilizing structured light images.
- Extraction of light stripes using HSV and gray space analysis.
- Application of a hole-filling algorithm for stripe integrity.
- Calculation of depth information to create a depth map.
- Segmentation of the depth map for defect analysis.
Main Results:
- Successful extraction and integrity of light stripes.
- Generation of a detailed depth map from structured light data.
- Accurate defect localization and measurement demonstrated.
- Feasibility and effectiveness of the proposed method validated.
Conclusions:
- The proposed two-stage structured light method significantly improves underwater defect inspection accuracy.
- This technique offers a viable alternative to traditional passive vision systems.
- The method is effective for precise defect localization and measurement in underwater environments.

