📕 Face recognition is the most popular bio-metric security-identification system being used all over the world. It is a dedicated process (much more versatile than the general object-recognition process) spanning different disciplines, which include cognitive science, computer vision, image processing, neural networks, neuroscience, pattern recognition, physiology and psychology. Partial face recognition is fast growing as the technique of choice during the past few years. It is one of the most striking applications of image analysis and understanding. Two reasons may be cited for this trend - the first is a wide range of commercial and law-enforcement applications and the second is depth of these technologies in terms of foreseeable enhancements during the next half-century. In fact, machine recognition of human partial faces as a challenging problem continues to attract researchers from disciplines.