Presently, there are many databases utilized for facial recognition that vary in lighting conditions, size, pose, expressions, the number of imaged subjects and occlusions. The earliest facial databases mostly consists of frontal images, such as the local data set acquired from 115 people at Brown University utilized in the early works in 1987. Nowadays, the facial databases were seen to capture the variations in pose, lighting, imaging angles, ethnicity, gender and facial expressions. Some of the most recent databases capture the variations in image sizes, compression, occlusions and are gathered from different sources such as social media and web 10, 11.
In this paper, we have presented a comprehensive survey of face databases for constrained and unconstrained environments. Section II describes the overview of various face databases. It focuses mostly on novel databases that are freely available for research purposes. Section III describes some of the recent face databases. Section IV compares the various popular face databases. Finally, Section V concludes the paper.