Justus Schwan Esam Ghaleb Enrique Hortal Stylianos Asteriadis High-performance and lightweight real-time deep face emotion recognition. 76-79 2017 SMAP https://doi.org/10.1109/SMAP.2017.8022671 conf/smap/2017 db/conf/smap/smap2017.html#SchwanGHA17