Investigating Nuisances in DCNN-based Face Recognition.

Face recognition "in the wild" has been revolutionized by the deployment of deep learning based approaches. In fact, it has been extensively demonstrated that Deep Convolutional Neural Networks (DCNNs) are powerful enough to overcome most of the limits that affected face recognition algorithms based on hand-crafted features. These include variations in illumination, pose, expression and occlusion, to mention some. The DCNNs discriminative power comes from the fact that low- and high-level representations are learned directly from the raw image data. As a consequence, we expect the performance of a DCNN to be influenced by the characteristics of the image/video data that are fed to the network, and their preprocessing. In this work, we present a thorough analysis of several aspects that impact on the use of DCNN for face recognition. The evaluation has been carried out from two main perspectives: the network architecture and the similarity measures used to compare deeply learned features; the data (source and quality) and their preprocessing (bounding box and alignment). Results obtained on the IJB-A, MegaFace, UMDFaces and YouTube Faces datasets indicate viable hints for designing, training and testing DCNNs. Taking into account the outcomes of the experimental evaluation, we show how competitive performance with respect to the state-of-the-art can be reached even with standard DCNN architectures and pipeline.