[1] [1] RAJAK A, MUNIR M, ABIDIN M, et al.A simple spectrometer using various LEDs and a photodiode sensor for photocatalytic performance evaluation［J］.Applied Mechanics & Materials, 2015, 771: 17-20.

[2] [2] HESHMAT H, GANGKAR M, ARIOMAND M, et al. Color stability of three composite resins following accelerated artificial aging: an in-vitro study［J］.Original Article, 2014, 26: 9-14.

[3] [3] TIAN Yi-bin, XU Zhi-hai, FENG Hua-jun, et al. Auto-focus Based on Skin Detection［J］. Acta Photonica Sinica, 2003, 32(1): 56-60.

[4] [4] WANG Chen, ZHENG Chen-dong, CHE Rong, et al. Researchon information quantityon aerial film and CCD［J］.Acta Photonica Sinica, 2007, 36: 259-261.

[5] [5] SHIH M. The development of a portable spectrophotometer for noncontact color measurement［J］.IEEE Transactions on Instrumentation & Measurement, 2004, 53(1): 155-162.

[6] [6] WEN Bo, YAN Chang-xiang. Optical design of portable spectrophotometer［J］. Applied Mechanics, 2011, 32(1): 18-22.

[7] [7] YOSHI O, HARDIS J E. Four-color matrix method for correction of tristimulus colorimeters［J］. Color & Imaging Conference, 1997, 23(4): 65-68.

[8] [8] WYBLE D, RICH D. Evaluation of methods for verifying the performance of color-measuring instruments. Part I: Repeatability［J］. Color Research & Application, 2007, 32(3): 166-175.

[9] [9] ROSENBERG S, ADKINS D. Online/robotic integrated thickness and color measurement［J］. Industrial Paint and Powder, 2006, 82(1): 21-25.

[10] [10] WANG Cong, JIN Shang-zhong, YUAN Kun. The improvement of the structure of double optical path d/0 in the spectrophotometer［J］. Opto-Electronic Engineering, 2012, 39: 134-137.

[11] [11] GREG R, ERIC N, MARK B. Spectrophotometer inter-instrument agreement on the color measured from reference and printed samples［C］. Proceedings of the Technical Association of the Graphic Arts, 2008, 232-251.

[12] [12] GU Yu-hai, JI Xin, LI Jiang-jie. Measuring stability improvement of photoelectric colorimeter［J］. Instrument Technique and Sensor, 2013, 9: 41-43.

[14] [14] FEN Hai-yan, Color measurement methods and basic principles［J］.Printing Industry, 2008, 6: 78-82.

[15] [15] YUAN K, YAN H, JIN S. The design of color spectrophotometer based on diffuse illumination and compatible SCE/SCI geometric condition［C］. SPIE, 2013, 90460V: 8-8.