Face Analysis Under Uncontrolled Conditions

Conclusion to Part 2

Benjamin ALLAERT¹, Ioan Marius BILASCO² and Chaabane DJERABA²

¹IMT Nord Europe, Lille, France

²University of Lille, France

C2.1. Summary

The facial expression analysis systems proposed in the literature achieve very good performance in conditions where the environment (uniform background scene, homogeneous light) and facial expressions (fixed pose, face facing the camera, high-intensity expression) are controlled. However, these data do not reflect the conditions encountered in a natural interaction situation (surveillance camera, videoconference) in which a person is free to move.

In this context, the environment (light changes, indoor/outdoor) as well as the interaction (pose variations, large displacements in the scene, face occlusion, variable expression intensity) are poorly constrained. All these constraints significantly decrease the performance of facial expression analysis systems and highlight several unresolved scientific issues.

Part 2 of this book has presented several contributions to address different problems related to the analysis of facial expressions in an image sequence, for an acquisition system where the interaction is natural. In particular, we have presented innovative solutions to the problems of facial motion intensity variations and pose variations.

C2.1.1. Variation of the intensity of the movement

In natural interaction situations, the intensities of facial movements tend to vary from one person to another because they do ...