Currently, reliable face detection and recognition are
		  becoming more important on mobile devices - e.g. to unlock
		  the screen. However, using only frontal face images for
		  authentication purposes can no longer be considered secure
		  under the assumption of easy availability of frontal
		  snapshots of the respective device owners from social
		  networks or other media. In most current implementations, a
		  sufficiently high-resolution face image displayed on
		  another mobile device will be enough to circumvent security
		  measures. In this paper, we analyze current methods to face
		  detection and recognition regarding their usability in the
		  mobile domain, and then propose an approach to a Face
		  Unlock system on a smart phone intended to be more secure
		  than current approaches while still being convenient to
		  use: we use both frontal and profile face information
		  available during a pan shot around the user’s head, by
		  combining camera images and movement sensor data. Current
		  results to face detection are promising, but reliable face
		  recognition needs further research.<br>
<br><pre>@inproceedings{Findling_12_TowardsFaceUnlock,
  author = {Findling, Rainhard and Mayrhofer, Ren\'e},
  title = {Towards Face Unlock: On the Difficulty of Reliably
  		  Detecting Faces on Mobile Phones},
  booktitle = {Proc. {MoMM} 2012: 10th International Conference on
  		  Advances in Mobile Computing and Multimedia},
  year = {2012},
  editor = {Khalil, Ismail},
  pages = {275--280},
  address = {New York, NY, USA},
  month = dec,
  publisher = {ACM},
  documenturl = {http://www.mayrhofer.eu.org/downloads/publications/MoMM2012-Mobile-Phone-Face-Detection.pdf},
  doi = {10.1145/2428955.2429008},
  eventurl = {http://iiwas.org/conferences/momm2012/},
  keywords = {Face detection; face recognition; mobile phone; user
  		  authentication},
  location = {Bali, Indonesia},
  pubtype = {conference},
  url = {https://dl.acm.org/citation.cfm?id=2429008}
}
</pre>