@inproceedings{kawahara2013pixel,
  title = {A Pixel-wise Varifocal Camera Model for Efficient Forward Projection and Linear Extrinsic Calibration of Underwater Cameras with Flat Housings},
  author = {Kawahara, Ryo and Nobuhara, Shohei and Matsuyama, Takashi},
  booktitle = {ICCV Workshop on Underwater Vision},
  year = {2013},
  pages = {819--824},
  doi = {10.1109/ICCVW.2013.112},
  url = {https://shohei.nobuhara.org/proj/pvcm/},
  pdf = {https://shohei.nobuhara.org/pdf/kawahara2014pixel.pdf}
}