ElSe pupil detector
===================

Algorithm and original source: Wolfgang Fuhl, Thiago C. Santini,
Thomas C. Kübler, Enkelejda Kasneci, University of Tübingen.

Reference: Fuhl, W., Santini, T., Kübler, T., Kasneci, E. (2016).
"ElSe: Ellipse Selection for Robust Pupil Detection in Real-World
Environments." *ETRA 2016*, vol. 14, 123-130.

Licence header from the upstream source (ElSe.h):

  Version 1.0, 17.12.2015, Copyright University of Tübingen.
  The code and the algorithm are for non-commercial use only.

The supporting Pupil / PupilDetectionMethod scaffolding distributed
alongside the upstream source is © 2018 Thiago Santini / University
of Tübingen, distributed under the following terms:

  Permission is hereby granted, free of charge, to any person obtaining
  a copy of this software, source code, and associated documentation
  files (the "Software") to use, copy, and modify the Software for
  academic use, subject to the following conditions:

  1) The above copyright notice and this permission notice shall be
  included in all copies or substantial portions of the Software.

  2) Modifications to the source code should be made available under
  free-for-academic-usage licenses.

  For commercial use, please contact the authors.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  SOFTWARE.
