Face recognition has witnessed a good deal of awareness because of its various applications in several fields like computer vision, security, pattern recognition and computer graphics, however still is a challenging and active research area. This paper has presented an extensive review of face databases for constrained and unconstrained Environments. Face databases are used for the face detection and recognition algorithm testing and they have been designed to analyze the effectiveness of recognition of face algorithms. The paper has focused mostly on novel databases that are freely available for the research purposes. Most of the popular face databases are briefly introduced and compared.
Over the last few years analysis in recognition of face has moved from 2D to 3D. The demand for 3D face data has caused the need of 3D databases. The paper initially gives an introduction of publicly present 2D and 3D face databases for constrained and unconstrained Environments. The presence of different databases requires a quantitative analysis of those databases so as to compare more precisely the executions of the different algorithms present in literature 8, 9, 10, 14, 15. The development of algorithms robust to illumination, pose, facial expression, age, occlusion changes demands databases of adequate size that involves cautiously controlled deviations of these features. Also, typical databases are required to relatively analyze techniques.
Presently several existing databases utilized for recognition of faces that contrast in lighting conditions, size, pose, expressions and occlusions. The previous facial databases mainly consists of frontal pictures, like the local set of data set collected from 115 people. Nowadays, the facial databases were observed to conquer the deviations in pose, illuminations, imaging directions, ethnicity, gender and facial expressions. Few most latest databases conquer the deviations in picture sizes, compression, occlusions and are collected from different origins like social media and web 10, 11.
This paper have presented an extensive 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.