Chenpi,or sun-dried mandarin orange peel,held significant economic and medicinal value,yet counterfeit and substandard products were prevalent in the current market.The aging year of Chenpi was a crucial quality indicator,but accurately determining it through manual inspection was challenging.This study proposed a rapid,non-destructive method to discern the aging year of Chenpi by integrating hyperspectral imaging with deep learning.A total of 480 Chenpi samples across four aging years were collected,and their near-infrared hyperspectral data(wavelength range:935.61~1720.23 nm)were obtained.A lightweight lD-Rep network was utilized to develop a classification model enhanced by a feature band selection technique using multi-layer gradient-weighted class activation mapping(M-Grad-CAM).This approach evaluated the importance of spectral bands across multiple Rep-block layers,indicating band significance while considering inter-band and remote correlations.To validate the effectiveness of the proposed method,feature bands obtained from machine learning methods such as partial least squares discriminant analysis(PLS-DA),random forest(RF),and support vector machine(SVM)were used as comparative methods.The results showed that,the lD-Rep full-spectrum model achieved an accuracy of 98.55%.When employing M-Grad-CAM for feature band selection and establishing a classification model based on the first nine feature bands,an accuracy greater than 90%could be achieved in feature band modeling.The accuracy reached 96.82%with 20 feature bands,significantly higher than that of the comparative models.This research effectively distinguishes Chenpi of different years using hyperspectral imaging technology,providing a methodological and theoretical basis for the development of portable detection instruments.
关键词
高光谱成像/陈皮/陈化年份/多层梯度加权类激活映射/特征波段
Key words
hyperspectral imaging/Chenpi/the aging year of Chenpi/multi-layer gradient-weighted class activation mapping(M-Grad-CAM)/feature band