Digital Multi-spectral Imaging Technique

• Main Authors: Wu, Chih-Ya, 吳至雅
• Other Authors: Tien, Chung-Hao
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/98067392828286924143

碩士 === 國立交通大學 === 光電工程研究所 === 104 === In this study, we focus on improving the multi-spectral imaging system which has been successfully developed. Firstly, in order to improve the stability of the system, we apply a new technique called weighted principal component analysis (wPCA). Implementation of this method provides the ability in selection of extracted principal eigenvectors. The result shows the reconstructed spectra based on wPCA are significantly improved in comparison to those obtained from the standard PCA. Then, we propose a new experimental framework to simulate an open environment. We establish a mathematical model by giving a calibration target and controllable ambient light. The experimental result shows that the average colorimetric errors and the RMS errors are decreased by 66.54% and 47.45%. Lastly, we utilize the multi-spectral imaging technique to detect bruises on apples and also build a system that can differentiate between good apples and bad apples. The identification rate is up to 87%.