An audiovisual and contextual approach for categorical and continuous emotion recognition in-the-wild

In this work we tackle the task of video-based audio-visual emotion recognition, within the premises of the 2nd Workshop and Competition on Affective Behavior Analysis in-the-wild (ABAW). Poor illumination conditions, head/body orientation and low image resolution constitute factors that can potentially hinder performance in case of methodologies that solely rely on the extraction and analysis of facial features. In order to alleviate this problem, we leverage bodily as well as contextual features, as part of a broader emotion recognition framework. We choose to use a standard CNN-RNN cascade as the backbone of our proposed model for sequence-to-sequence (seq2seq) learning. Apart from learning through the RGB input modality, we construct an aural stream which operates on sequences of extracted mel-spectrograms. Our extensive experiments on the challenging and newly assembled Affect-in-the-wild-2 (Aff-Wild2) dataset verify the superiority of our methods over existing approaches, while by properly incorporating all of the aforementioned modules in a network ensemble, we manage to surpass the previous best published recognition scores, in the official validation set. All the code was implemented using PyTorch\footnote{\url{https://pytorch.org/}} and is publicly available\footnote{\url{https://github.com/PanosAntoniadis/NTUA-ABAW2021}}.