title: What's Wrong with the Murals at the Mogao Grottoes: A Near-Infrared Hyperspectral Imaging Method.
abstract: Although a significant amount of work has been performed to preserve the ancient murals in the Mogao Grottoes by Dunhuang Cultural Research, non-contact methods need to be developed to effectively evaluate the degree of flaking of the murals. In this study, we propose to evaluate the flaking by automatically analyzing hyperspectral images that were scanned at the site. Murals with various degrees of flaking were scanned in the 126th cave using a near-infrared (NIR) hyperspectral camera with a spectral range of approximately 900 to 1700 nm. The regions of interest (ROIs) of the murals were manually labeled and grouped into four levels: normal, slight, moderate, and severe. The average spectral data from each ROI and its group label were used to train our classification model. To predict the degree of flaking, we adopted four algorithms: deep belief networks (DBNs), partial least squares regression (PLSR), principal component analysis with a support vector machine (PCA + SVM) and principal component analysis with an artificial neural network (PCA + ANN). The experimental results show the effectiveness of our method. In particular, better results are obtained using DBNs when the training data contain a significant amount of striping noise.
authors.affiliation: School of Computer Science, Tianjin University, Tianjin, China.
authors.forename: Meijun
authors.initials: M
authors.lastname: Sun
authors.affiliation: School of Computer Science, Tianjin University, Tianjin, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Zhang
authors.affiliation: School of Computer Software, Tianjin University, Tianjin, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Centre for excellence in Signal and Image Processing, University of Strathclyde, Glasgow, UK.
authors.forename: Jinchang
authors.initials: J
authors.lastname: Ren
authors.affiliation: Dunhuang Academy, Gansu, China.
authors.forename: Bolong
authors.initials: B
authors.lastname: Chai
authors.affiliation: School of Computer Science, Tianjin University, Tianjin, China.
authors.forename: Jizhou
authors.initials: J
authors.lastname: Sun