Facial emotional classification: from a discrete perspective to a continuous emotional space

• Published in: Pattern analysis and applications : PAA Vol. 16; no. 1; pp. 41 - 54
• Main Authors: Hupont, Isabelle, Baldassarri, Sandra, Cerezo, Eva
• Format: Journal Article
• Language: English
• Published: London Springer-Verlag 01.02.2013; Springer
• Subjects: Applied sciences; Artificial intelligence; Computer Science; Computer science; control theory; systems; Computer systems and distributed systems. User interface; Exact sciences and technology; Pattern Recognition; Pattern recognition. Digital image processing. Computational geometry; Software; Theoretical Advances; Affective computing; Algorithms; Intelligent user interfaces; Facial expression analysis; Ethnic origin; Man machine system; Cognition; Emotion emotionality; User interface; Classification; Facies; Database; Age; Facial expression
• ISSN: 1433-7541; 1433-755X
• DOI: 10.1007/s10044-012-0286-6

User emotion detection is a very useful input to develop affective computing strategies in modern human computer interaction. In this paper, an effective system for facial emotional classification is described. The main distinguishing feature of our work is that the system does not simply provide a classification in terms of a set of discrete emotional labels, but that it operates in a continuous 2D emotional space enabling a wide range of intermediary emotional states to be obtained. As output, an expressional face is represented as a point in a 2D space characterized by evaluation and activation factors. The classification method is based on a novel combination of five classifiers and takes into consideration human assessment for the evaluation of the results. The system has been tested with an extensive universal database so that it is capable of analyzing any subject, male or female of any age and ethnicity. The results are very encouraging and show that our classification strategy is consistent with human brain emotional classification mechanisms.