@article{Zhang2007Moving,
  title={Moving Cast Shadows Detection Using Ratio Edge},
  author={Zhang, Wei and Fang, Xiang Zhong and Yang, Xiaokang K. and Wu, Q. M. Jonathan},
  journal={IEEE Transactions on Multimedia},
  volume={9},
  number={6},
  pages={1202-1214},
  year={2007},
}