[1] [1] Wang Y W, Ding W, Kou L P, et al. A non-destructive method to assess freshness of raw bovine milk using FT-NIR spectroscopy［J］. Journal of Food Science and Technology, 2015, 52(8): 5305-5310.

[2] [2] Chu Xiaoli, Lu Wanzhen. Research and application progress of near infrared spectroscopy analytical technology in China in the past five years［J］. Spectroscopy and Spectral Analysis, 2014, 34(10): 2595-2605.

[3] [3] Fu Bo, Hu Yongxiang, Liu Rong, et al. Near-infrared measurement with medium concentration sample as reference［J］. Acta Optica Sinica, 2016, 36(2): 0230003.

[4] [4] Lu Wanzhen. Modern near infrared spectra analysis technology［M］. Beijing: China Petrochemical Press, 2000.

[5] [5] Andersson C A. Direct orthogonalization［J］. Chemometrics and Intelligent Laboratory Systems, 1999, 47(1): 51-63.

[6] [6] Fearn T. On orthogonal signal correction［J］. Chemometrics and Intelligent Laboratory Systems, 2000, 50(1): 47-52.

[7] [7] Li Yaping, Zhang Guangjun, Li Qingbo. Application of O2-PLS in experimental study on non-invasive measurement of blood glucose［J］. Acta Optica Sinica, 2010, 30(3): 854-860.

[8] [8] Lu Wanzhen, Yuan Hongfu, Chu Xiaoli. Near infrared spectrometer［M］. Beijing: Chemical Industry Press, 2010: 27-30.

[9] [9] Chu Xiaoli, Yuan Hongfu, Lu Wanzhen. Progress and application of spectral data pretreatment and wavelength selection methods in NIR analytical technique［J］. Progress in Chemistry, 2004,16(4): 528-542.

[10] [10] Wang L J, Zhou Z, Qin Y, et al. Analysis of data mining method for near infrared spectral data of dairy products based orthogonality［C］. International Conference of Electronic Engineering and Information Science, 2014, 981: 641-646.

[11] [11] Gonzalez R C, Woods R E. Digital image processing［M］. Ruan Qiuqi, Transl. 2nd ed. Beijing: Publishing House of Electronics Industry, 2007: 70-84.

[12] [12] Lim J, Kim G, Mo C, et al. Detection of melamine in milk powders using near-infrared hyperspectral imaging combined with regression coefficient of partial least square regression model［J］. Talanta, 2016, 151: 183-191.

[13] [13] Yu Shimiao, Lu Wei, Liang Kun, et al. Study on prediction of germination rate of rice seeds using hyperspectral imaging combined with PCA and GRNN［J］. Laser & Optoelectronics Progress, 2015, 52(11): 113001.

[14] [14] Chen Wenfei. Research of image enhancement based on probability theory［D］. Wuhan: Wuhan University, 2011.

[15] [15] Nie Chao. Efficient image enhancement algorithm research based on histogram［D］. Hangzhou: Hangzhou Dianzi University, 2014: 27-29.

[16] [16] Liu Bo, Hu Zhengping, Wang Chengru. Multi-level interactive image enhancement algorithm based on fuzzy relaxation iterative procedure［J］. Optical Technique, 2009, 35(1): 131-134.

[17] [17] Wang Lijie. Research on rapid measuring method and system for milk constituents detecting by near infared spectrum［D］. Harbin: Harbin University of Science and Technology, 2006: 80-82.