Group-Level Emotion Recognition using Deep Models with A Four-stream Hybrid Network

Group-level Emotion Recognition (GER) in the wild is a challenging task gaining lots of attention. Most recent works utilized two channels of information, a channel involving only faces and a channel containing the whole image, to solve this problem. However, modeling the relationship between faces and scene in a global image remains challenging. In this paper, we proposed a novel face-location aware global network, capturing the face location information in the form of an attention heatmap to better model such relationships. We also proposed a multi-scale face network to infer the group-level emotion from individual faces, which explicitly handles high variance in image and face size, as images in the wild are collected from different sources with different resolutions. In addition, a global blurred stream was developed to explicitly learn and extract the scene-only features. Finally, we proposed a four-stream hybrid network, consisting of the face-location aware global stream, the multi-scale face stream, a global blurred stream, and a global stream, to address the GER task, and showed the effectiveness of our method in GER sub-challenge, a part of the six Emotion Recognition in the Wild (EmotiW 2018) [10] Challenge. The proposed method achieved 65.59% and 78.39% accuracy on the testing and validation sets, respectively, and is ranked the third place on the leaderboard.