@inproceedings{smi-smi-05-vplsm,
  author = {Lyndon N. Smith and Melvyn L. Smith},
  title = {The Virtual Point Light Source Model the Practical Realisation of Photometric Stereo for Dynamic Surface Inspection},
  booktitle = {Proc.~ICIAP 2005 - 13th~International Conference on Image Analysis and Processing},
  year = 2005,
  pages = {495--502}
}