Optimized Periocular Template Selection for Human Recognition

Table 1

Comparison of biometric traits present in human face.

Trait	Advantages	Possible challenges
Iris	High-dimensional feature can be extracted, difficult to spoof, permanence of iris, secured within eye folds, and can be captured in noninvasive way	Yields accuracy in NIR images than VS images, cost of NIR acquisition device is high, low recognition accuracy in unconstrained scenarios, low recognition accuracy for low resolution, occlusion due to use of lens, eye may close at the time of capture, do not work for keratoconus and keratitis patients
Face	Easy to acquire, yields accuracy in VS images, most available in criminal investigations	Not socially acceptable for some religions, full face image makes database large, variation with expression and age
Periocular	Can be captured with face/iris region without extra acquisition cost	Can be occluded by spectacle, less features in case of infants
Lip	Existence of both global and local features	Difficult to acquire, less acceptable socially, shape changes with human expression
Ear	Easy segmentation due to presence of contrast in the vicinity	Difficult to acquire and can be partially occluded by hair