Xie, X., Mirmehdi, M., & Thomas, B. (2006). Colour tonality inspection using eigenspace features. Machine Vision and Applications, 16(6), pp. 364-373. doi:10.1007/s00138-005-0008-9

Xie, Xianghua, Majid Mirmehdi, and Barry Thomas. "Colour Tonality Inspection Using Eigenspace Features." Machine Vision and Applications 16, no. 6 (2006): 364-373.

Xie, Xianghua, Majid Mirmehdi, and Barry Thomas. "Colour Tonality Inspection Using Eigenspace Features." Machine Vision and Applications 16.6 (2006): 364-373.