Techno Press
You logged in as. Techno Press

Smart Structures and Systems
  Volume 29, Number 1, January 2022 , pages 207-220
DOI: https://doi.org/10.12989/sss.2022.29.1.207
 


Impacts of label quality on performance of steel fatigue crack recognition using deep learning-based image segmentation
Shun-Hsiang Hsu, Ting-Wei Chang and Chia-Ming Chang

 
Abstract
    Structural health monitoring (SHM) plays a vital role in the maintenance and operation of constructions. In recent years, autonomous inspection has received considerable attention because conventional monitoring methods are inefficient and expensive to some extent. To develop autonomous inspection, a potential approach of crack identification is needed to locate defects. Therefore, this study exploits two deep learning-based segmentation models, DeepLabv3+ and Mask R-CNN, for crack segmentation because these two segmentation models can outperform other similar models on public datasets. Additionally, impacts of label quality on model performance are explored to obtain an empirical guideline on the preparation of image datasets. The influence of image cropping and label refining are also investigated, and different strategies are applied to the dataset, resulting in six alternated datasets. By conducting experiments with these datasets, the highest mean Intersection-over-Union (mIoU), 75%, is achieved by Mask R-CNN. The rise in the percentage of annotations by image cropping improves model performance while the label refining has opposite effects on the two models. As the label refining results in fewer error annotations of cracks, this modification enhances the performance of DeepLabv3+. Instead, the performance of Mask R-CNN decreases because fragmented annotations may mistake an instance as multiple instances. To sum up, both DeepLabv3+ and Mask R-CNN are capable of crack identification, and an empirical guideline on the data preparation is presented to strengthen identification successfulness via image cropping and label refining.
 
Key Words
    crack recognition; deep learning; image segmentation; label quality
 
Address
(1) Shun-Hsiang Hsu:
NCREE-NTUCE Joint Artificial Intelligence Research Center, No. 200, Sec. 3, Xinhai Rd., Da'an Dist., Taipei City 106219, Taiwan (R.O.C.);
(2) Ting-Wei Chang, Chia-Ming Chang:
Department of Civil Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Da'an Dist., Taipei City 106319, Taiwan (R.O.C.).
 

Techno-Press: Publishers of international journals and conference proceedings.       Copyright © 2026 Techno Press
P.O. Box 33, Yuseong, Daejeon 305-600 Korea, Tel: +82-42-828-7996, Fax : +82-42-828-7997, Email: admin@techno-press.com