BibTex Entry:

@Article{WIN05:Lightwaving,
  author  = {Holger Winnem\"{o}eller and Ankit Mohan and Jack Tumblin and Bruce Gooch},
  title   = {Light Waving: Estimating Light Positions From Photographs Alone},
  abstract= {We present an algorithm to automatically estimate three-dimensional 
             light positions from an unordered set of images. We collect images 
             using a single stationary camera while manually moving a light source 
             around an object. Rather than measuring light positions directly, 
             the algorithm extracts a three-dimensional manifold of positions from 
             the images using dimensionality reduction techniques. This obviates 
             the need for calibration and specialized equipment, making our 
             approach inexpensive, portable and applicable to objects of almost 
             any size. We demonstrate our results using image-based relighting 
             applications.},
  journal = {Computer Graphics Forum},
  volume  = {24},
  number  = {3},
  year    = {2005},
  pages   = {433--438}
}