1. School of Remote Sensing Information Engineering,Wuhan University,Wuhan 430072,China
2. Aerospace Information Research Institute, Henan Academy of Sciences, Zhengzhou 450046, China
Abstract:Cover glass is an important component of intelligent terminal products, with a smooth, transparent surface and complex and variable characteristics. Its appearance inspection is one of the important challenges in optical imaging detection. Currently, conventional detection methods are mainly based on visible light images. Still, due to texture similarity, stains are often misjudged as defects, making good products judged as defective, thereby increasing industrial costs. To overcome the above problems, this article proposes a method for detecting stains and defects on cover glass based on hyperspectral technology. This method selects the hyperspectral data's optimal feature spectrum and establishes a quantitative detection model to select key feature bands and accurately detect stains and defects. This article utilizes the optical properties of the ink and AA transparent areas and adopts a linear light source transmission imaging method. Through professional hyperspectral line scanning equipment, 50 hyperspectral images of mobile phone cover glass were effectively collected. A stain defect dataset was created, including 500 samples of clean and flawless cover plates and 100 samples of four types of stains and scratch defects, including glass fingerprints, adhesive substances, cleaning agents, and dust. Based on the above hyperspectral image dataset, this paper constructs a band selection method that comprehensively considers the spectral characteristics of stains and defects and the contribution and importance of each feature band. Eight feature bands (502, 526, 567, 689, 711, 789, 818, and 888 nm) that can effectively distinguish stains and defects are selected. Using machine learning algorithms for detection, experimental results show that 8 selected hyperspectral bands perform well in distinguishing stains and defects, with an accuracy rate of 95.4% and an error rate of only 4.7%. Hyperspectral imaging can capture the differences between defects and stains in the spectrum, achieving more accurate detection and providing a feasible new method for quality inspection of mobile phone cover glass. It can provide a reference for designing low-cost hyperspectral defect and stain detection cameras in practical applications.
Key words:Hyperspectral; Stain defect detection; Feature band selection; Random forest
沈冠廷,饶可奕,方瑞欣,张学敏,巫兆聪. 盖板玻璃外观检测的高光谱线扫成像方法[J]. 光谱学与光谱分析, 2025, 45(03): 616-622.
SHEN Guan-ting, RAO Ke-yi, FANG Rui-xin, ZHANG Xue-min, WU Zhao-cong. A Method for Classifying Stains and Defects on Mobile Phone Cover Glass Based on Hyperspectral Line Scan Imaging. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2025, 45(03): 616-622.
[1] CUI Yan,PENG Ke,YANG Yu-e,et al(崔 焱,彭 可,杨玉娥,等). Manufacturing Automation(制造业自动化),2023,45(7):75.
[2] HE Yi-lin,TAO Xiao(贺旖琳,陶 肖). Industrial Control Computer(工业控制计算机),2022,35(12):74.
[3] Latham V H, Nixon M S, Mayers C. Glass Technology, 1986,27:188.
[4] Li C,Zhang X,Huang Y,et al. Computers & Industrial Engineering, 2020,146:106530.
[5] ZHANG Jian-guo,LI Ying,QI Jia-kun,et al(张建国,李 颖,齐家坤,等). Journal of Applied Optics(应用光学),2020,41(5):984.
[6] Jian C X, Gao J, Ao Y H. Applied Soft Computing,2017,52:348.
[7] LUO Gen,NI Jun(罗 根,倪 军). Journal of Electronic Measurement and Instrumentation(电子测量与仪器学报),2018,32(2):92.
[8] Takhar G,Prakash C,Mittal N,et al. Comparative Analysis of Background Subtraction Techniques and Application, International Conference on Recent Advances & Innovations in Engineering IEEE, 2017.
[9] Zhang Z, Xu Y,Yang J,et al. IEEE Access, 2015, 3: 490.
[10] Li D, Liang L Q, Zhang W J,et al. The International Journal of Advanced Manufacturing Technology,2014,73(9):1605.
[11] Tsai D M,Tseng Y H,Fan S K M. Defect Inspection of Liquid-Crystal-Display (LCD) Panels in Repetilive Pattern Images Using 2D Fourier Image Reconstruction, International Conference on Autonomic and Autonomous Systems,2018.
[12] LI Wei-chao,CHEN Zhi-hao,ZHANG Xie,et al(李伟朝,陈志豪,张 勰,等). Computer Measurement & Control(计算机测量与控制),2023,31(7):99.
[13] WU Ji-gang,CHENG Yuan,SHAO Jun,et al(伍济钢,成 远,邵 俊,等). Chinese Journal of Liquid Crystals and Displays(液晶与显示),2021,36(12):1728.
[14] WU Chuang,YU Da-yong(吴 闯,于大泳). Software Engineering(软件工程),2021,24(12):6.