• Spectroscopy and Spectral Analysis
  • Vol. 29, Issue 12, 3295 (2009)
WU Di1、*, CAO Fang1, ZHANG Hao2, SUN Guang-ming1, FENG Lei1, and HE Yong1
Author Affiliations
  • 1[in Chinese]
  • 2[in Chinese]
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    DOI: Cite this Article
    WU Di, CAO Fang, ZHANG Hao, SUN Guang-ming, FENG Lei, HE Yong. Study on Disease Level Classification of Rice Panicle Blast Based on Visible and Near Infrared Spectroscopy[J]. Spectroscopy and Spectral Analysis, 2009, 29(12): 3295 Copy Citation Text show less

    Abstract

    Visible and near infrared(Vis-NIR)spectroscopy was used to fast and non-destructively classify the dis-ease levels of rice panicle blast. Reflectance spectra between 325 and 1075 nm were measured. Kennard-Stone algorithm was operated to separate samples into calibration and prediction sets. Different spectral pretreatment methods, including standard normal variate(SNV) and multiplicative scatter correction(MSC), were used for the spectral pretreatment before further spectral analysis. A hybrid wavelength variable selection method which is combined with uninformative variable elimination(UVE) and successive projections algorithm(SPA) was operated to select effective wavelength variables from original spectra, SNV pretreated spectra and MSC pretreated spectra, respectively. UVE was firstly operated to remove uninformative wavelength variables from the fullspectrum. Then SPA selected the effective wavelength variables with less colinearity after UVE. Leasts quare-support vector machine(LS-SVM) was used as the calibration method for the spectral analysis in this study. The selected effective wave-lengths were set as input variables of LS-SVM model. The LS-SVM model established basedon SNV-UVE-SPA obtained the best results. Only six effective wavelengths(459,546,569,590,775 and 981 nm) were selected from the fullspectrum which has 600 wavelength variables by UVE-SPA, and their LS-SVM model’s performance was further improved. For SNV-UVE-SPA-LS-SVM model, coefficient of determination for prediction set(R2), root mean square error for prediction (RMSEP) and residual predictivedeviation (RPD) were 0.979, 0.507 and 6.580, respectively. The overall results indicate that Vis-NIR spectroscopy is a feasible way to classify disease levels of rice panicle blast fast and non-destructively. UVE-SPA is an efficient variable selection method for the spectral analysis, and their selected effective wavelengths can represent the useful information of the fullspectrum and have higher signal/noise ratio and less colinearity.
    WU Di, CAO Fang, ZHANG Hao, SUN Guang-ming, FENG Lei, HE Yong. Study on Disease Level Classification of Rice Panicle Blast Based on Visible and Near Infrared Spectroscopy[J]. Spectroscopy and Spectral Analysis, 2009, 29(12): 3295
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