@Article{KCLee05,
  author =  "K.C. Lee and J. Ho and D. Kriegman",
  title =   "Acquiring Linear Subspaces for Face Recognition under Variable Lighting ",
  journal = "IEEE Trans. Pattern Anal. Mach. Intelligence",
  year =  2005,
  volume = 27,
  number = 5,
  pages= "684-698"}