Method partially based on the excellent work described in:
 Cheong, Jin Hyun, et al. "Py-feat: Python facial expression analysis toolbox." arXiv preprint arXiv:2104.03509 (2021).  Namba, Shushi, Wataru Sato, and Sakiko Yoshikawa. "Viewpoint Robustness of Automated Facial Action Unit Detection Systems." Applied Sciences 11.23 (2021): 11171.  Carranza, Karmelo Antonio Lazaro R., et al. "Expression tracking with OpenCV deep learning for a development of emotionally aware chatbots." 2019 7th international conference on robot intelligence technology and applications (RiTA). IEEE, 2019.
Terms of Service
All images are compared against multiple databases of illegal images such that any match against this database will be reported to the appropriate authorities.
No warranty expressed or implied is provided as to the functioning of this service.
Attempting to process sexually explicit, violent, hateful or other objectionable material may result in a site-wide ban from this service.
All images are stored temporarily server-side insofar as to complete the image or video processing task.
When processing is complete, both the input and processed image are irretrievably destroyed.
When processing is complete, the resulting image or video is stored for (1) one hour before being irretrievably destroyed.