1. Choras M (2010) The lip as a biometric. Pattern Anal Appl 13(1):105–112
2. Thakur P, Madaan N (2014) A survey of image segmentation techniques. Int J Res Comput Appl Robot 2(4):158–165
3. Zaitoun NM, Aqel MJ (2015) Survey on image segmentation techniques. In: International conference on communication, management and information technology. ScienceDirect, Prague, pp 797–806
4. Bazen AM, Gerez SH (2001) Segmentation of fingerprint images. In: ProRISC workshop on circuits, systems and signal processing. Veldhoven, The Netherlands
5. Raju PDR, Neelima G (2012) Image segmentation by using histogram thresholding. Int J Comput Sci Eng Technol 2(1):776–779