The analysis of human emotions has an extremely relevant impact on everyday life. There are many characteristics that make emotions transpire: they can manifest themselves through voice, gestures, or facial expressions. Many researchers have questioned what the most effective methodology is to objectively analyse what the standard markers in the recognition of a particular emotion are and, in this regard, the field of facial expressions has been widely studied. With the advent of Artificial Intelligence (AI), which aims to create a human-computer interaction that improves over time, the study of facial expressions has been directed towards a more automated analysis, which can be used without human intervention.