Face recognition is one of the most interesting and challenging research area in the past decades. The face recognition system has used facial databases which can verify whether the given facial image is found in the database or not. It is very popular in biometric authentications and surveillance and they do not require the user intervention. Face recognition technique is definitely an emerging multi-disciplinary subject that facilitates discovering of previous unknown patterns from large amount of data. This paper provides the basic concepts of Facial Recognition and its essential characteristics. Face recognition in IoT, biometric system, crowd detection are also discussed in this paper.

Face Detection, Face Recognition, Biometrics, IoT based face recognition, Applications

[1]. Kosov S., Scherbaum K., Faber K., Thormahlen T. and Seidel H.-P., "Rapid stereo-vision enhanced face detection", Image Processing (ICIP), 2009 16th IEEE International Conference on, IEEE, 1221-1224, 2009.
[2]. P.J. Phillips, H. Moon, S.A. Rizvi and P.J. Rauss, “The feret evaluation methodology for face-recognition algorithms”, IEEE Trans. Pattern Anal. Mach. Intell. 22 (10) (20 0 0) 1090–1104.
[3]. R. Gross, I. Matthews, J. Cohn, T. Kanade and S. Baker, Multi-pie, Image Vis. Com-put. 28 (5) (2010) 807–813.
[4]. G.B. Huang, M. Ramesh, T. Berg, E. Learned-Miller, “Labeled Faces in the Wild: A Database for Studying Face Recognition in Unconstrained Environments”, Tech-nical Report 07-49, University of Massachusetts, Amherst, 2007.
[5]. C. Ding and D. Tao, “A comprehensive survey on pose-invariant face recognition”, ACM Trans. Intell. Syst. Technol.7 (3) (2016) 37.
[6]. X. Zhu, Z. Lei, J. Yan, D. Yi and S.Z. Li, “High-fidelity pose and expression normalization for face recognition in the wild”, Proceedings of the IEEE Conference on Computer Vision and Pattern Recogn”ition, 2015, pp. 787–796 .
[7]. J. Yim, H. Jung, B. Yoo, C. Choi, D. Park and J. Kim, “Rotating your face using multi–task deep neural network”, Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition, 2015, pp. 676–684 .
[8]. Christos Sagonas, YannisPanagakis, StefanosZafeiriou and MajaPantic, “Robust Statistical Face Frontalization”, ICCV, IEEE Xplore.
[9]. Jawad Nagi, Syed Khaleel Ahmed and Farrukh Nagi, “A MATLAB based Face Recognition System using Image Processing and Neural Networks” 4th International Colloquium on Signal Processing and its Applications, March 7-9, 2008, Kuala Lumpur, Malaysia. Faculty of Electrical Engineering, UiTM Shah Alam, Malaysia. ISBN: 978-983-42747-9-5
[10]. Divyarajsinh N. Parmar and Brijesh B. Mehta, “Face Recognition Methods & Applications” Divyarajsinh N Parmar et al ,Int.J.Computer Technology & Applications,Vol 4 (1),84-86, ISSN:2229-6093.
[11]. Kim, Kwang In, Keechul Jung, and Hang Joon Kim. "Face recognition using kernel principal component analysis" Signal Processing Letters, IEEE 9.2 (2002): 40-42.
[12]. Gan, Jun-ying, Dang-pei Zhou, and Chun-zhi Li. "A method for improved PCA in face recognition" International Journal of Information Technology 11.11 (2005): 79-85.
[13]. Timotius, Ivanna K., Iwan Setyawan, and Andreas A. Febrianto. "Face recognition between two person using kernel principal component analysis and support vector machines" International Journal on Electrical Engineering and Informatics 2.1 (2010): 55-63.
[14]. El Traboulsi et al. "Matrix Exponential based Semi-supervised Discriminant Embedding for Image Classification" Pattern Recognition (2016).
[15]. Vieira, MatheusAlves, et al. "Object based image analysis and data mining applied to a remotely sensed Landsat time-series to map sugarcane over large areas" Remote Sensing of Environment 123 (2012): 553-562.
[16]. Samir K. Bandyopadhyay, “A Method for Face Segmentation, Facial Feature Extraction and Tracking”, IJCSET | April 2011 | Vol 1, Issue 3,137-139
[17]. Dr. S.Vijayarani and M.Vinupriya, “Performance Analysis of Canny and Sobel Edge Detection Algorithms in Image Mining”, International Journal of Innovative Research in Computerand Communication Engineering, ISSN (Online): 2320-9801, ISSN (Print): 2320-9798, Vol.1, Issue 8, October 2013.
[18]. Juneja. Mamta , Sandhu .Parvinder Singh, “Performance Evaluation of Edge Detection Techniques for Images in Spatial Domain”, International Journal of Computer Theory and Engineering, Vol. 1, No. 5, December, 2009, 1793-8201.
[19]. Kirby, M. & Sirovich, L. (1990). “Application of the Karhunen-Loeve procedure for the characterization of human faces”, IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 12, No. 1, pp. 103-107.
[20]. Tjahyadi, R.; Liu, W.; An, S. & Venkatesh, S.(2004) “Face Recognition via the Overlapping Energy Histogram”, IJCAI, pp.2891-2896, 2007.
[21]. Chen W., Er M.J., Wu S., “PCA and LDA in DCT Domain”, Pattern Recognition Letters, Vol. 26, Issue 15, November 2005, pp. 2474-2482
[22]. Delac, K., Grgic, M., “Face Recognition”, I-Tech Education and Publishing, ISBN 978-3-902613-03-5, Vienna, July 2007, 558 pages Delac K., Grgic M., Grgic S., Image Compression Effects in Face Recognition Systems, In: Face Recognition
[23]. Yang, M.; Kriegman, D. & Ahuja, N. (2001). Detecting faces in images: A survey, IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 23, No. 1, pp. 34-58.
[24]. Shashua, A. & Riklin-Raviv, T. (2001). The quotient image: Classbased re-rendering and recognition with varying illuminations, IEEE Transactions Pattern Analysis and Machine Intelligence, Vol. 23, No. 2, pp. 129 – 139
[25]. Silva P. & Rosa, A.S. (2003). Face recognition based on eigeneyes. Pattern Recognition and Image Analysis, Vol. 13, No. 2, pp. 335–338
[26]. Pamudurthy, S.; Guan, E.; Mueller, K. & Rafailovich M. (2005). Dynamic approach for face recognition using digital image skin correlation. Proceedings of Audio- and Video-based Biometric Person Authentication.
[27]. Alexander, J. & Smith, (2003). Engineering privacy in public: Confounding face recognition, privacy enhancing technologies. Proceedings of International Workshop on Privacy Enhancing Technologies.
[28]. Sandesh Kulkarni, Minakshee Bagul, Akansha Dukare and Prof. Archana Gaikwad, “Face RecognitionSystem Using IoT” International Journal of Advanced Research in Computer Engineering & Technology (IJARCET)Volume 6, Issue 11, November 2017,ISSN:2278–1323.
[29]. Renu Bhatia, “Biometrics and Face Recognition Techniques” International Journal of Advanced Research in Computer Science and Software Engineering” Volume 3, Issue 5, May 2013ISSN: 2277 128X
[30]. Priyanka, “A Study on Facial Feature Extraction and Facial Recognition Approaches” International Journal of Computer Science and Mobile Computing, Vol.4 Issue.5, May-2015, pg. 166-174
[31]. D. Chaudhari, Mayur & Ghotkar, Archana. (2018). A Study on Crowd Detection and Density Analysis for Safety Control. International Journal of Computer Sciences and Engineering. 6. 424-428. 10.26438/ijcse/v6i4.424428.
[32]. B.Mohd. Jabarullah, Sandeep Saxena and Dr. C. Nelson Kennedy Babu, “Survey on Noise Removal in Digital Images”, IOSR Journal of Computer Engineering (IOSRJCE), ISSN: 2278-0661, ISBN: 2278-8727 Volume 6, Issue 4, Oct. 2012.
[33]. Scott Tan Yeh Ping, Chun Hui Weng, Boonping Lau, “Face Detection through Template Matching and Color Segmentation”.