Face Recognition under Varying Illumination Using Green’s Functionbased Bidimensional Empirical Mode Decomposition and GradientfacesZhi-Jun Yang, Xue He, Wen-Yi Xiong and Xiang-Fei NieITM Web Conf., 7 (2016) 01015DOI: https://doi.org/10.1051/itmconf/20160701015