Authors:
Paul Audain Desrosiers
1
;
Yasmine Bennis
2
;
Boulbaba Ben Amor
1
;
Mohamed Daoudi
1
and
Pierre Guerreschi
2
Affiliations:
1
Telecom Lille and CRIStAL (UMR CNRS 9189), France
;
2
Université of Lille 2 Droit et Santé, France
Keyword(s):
4D Faces, Dense Scalar Fields, Face Asymmetry, Facial Paralysis, Dynamic Faces.
Related
Ontology
Subjects/Areas/Topics:
Applications and Services
;
Computer Vision, Visualization and Computer Graphics
;
Image and Video Analysis
;
Medical Image Applications
;
Shape Representation and Matching
Abstract:
This paper addresses the problem of quantifying the facial asymmetry from dynamic 3D data. We investigate
here the role of 4D (i.e. 3D+time) data to reveal the amount of both static and dynamic asymmetry, in a clinical
use-case of facial paralysis. The final goal is to provide tools and solutions to clinicians for facial paralysis
assessment and monitoring, which can provide qualitative and quantitative evaluations. To this end, the approach
proposed here consider 3D facial sequences and adopt a recently-developed Riemannian approach for
facial deformation analysis. After a preprocessing step, each frame of a given 3D sequence is approximated
by an indexed collection of elastic radial curves. Riemannian shape analysis of obtained curves and their symmetrical
counterparts, both elements of the same shape space, give rise to a feature vector, called Dense Scalar
Fields (DSFs). The use of these DSFs reveals the amount of bilateral asymmetry of the face, when conveying
expressions. That
is, given a 3D frame, it is first reflected with respect to the YZ-plane, then compared to the
obtained reflection using the DSFs. To exemplify the use of the proposed approach, a new dataset have been
collected (of patients) before and after injecting Botulinum Toxin (BT) in related facial muscles. Experimental
results obtained on this dataset show that the proposed approach allows clinicians to evaluate the facial
asymmetry before and after the medical treatment.
(More)