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Recovering facial shape using a statistical model of surface normal direction

Smith, William A. P. (orcid.org/0000-0002-6047-0413) and Hancock, Edwin R. (orcid.org/0000-0003-4496-2028) (2006) Recovering facial shape using a statistical model of surface normal direction. IEEE Transactions on Pattern Analysis and Machine Intelligence. pp. 1914-1930. ISSN 0162-8828

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In this paper, we show how a statistical model of facial shape can be embedded within a shape-from-shading algorithm. We describe how facial shape can be captured using a statistical model of variations in surface normal direction. To construct this model, we make use of the azimuthal equidistant projection to map the distribution of surface normals from the polar representation on a unit sphere to Cartesian points on a local tangent plane. The distribution of surface normal directions is captured using the covariance matrix for the projected point positions. The eigenvectors of the covariance matrix define the modes of shape-variation in the fields of transformed surface normals. We show how this model can be trained using surface normal data acquired from range images and how to fit the model to intensity images of faces using constraints on the surface normal direction provided by Lambert's law. We demonstrate that the combination of a global statistical constraint and local irradiance constraint yields an efficient and accurate approach to facial shape recovery and is capable of recovering fine local surface details. We assess the accuracy of the technique on a variety of images with ground truth and real-world images.

Item Type: Article
Copyright, Publisher and Additional Information: Copyright © 2006 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.
Keywords: shape-from-shading,albedo estimation,directional statistics,illumination,face modeling,FACE RECOGNITION,IMAGES,CONSTRAINTS,PERCEPTION,EXTRACTION
Institution: The University of York
Academic Units: The University of York > Computer Science (York)
Depositing User: Repository Officer
Date Deposited: 21 Feb 2007
Last Modified: 30 May 2016 15:17
Published Version: http://dx.doi.org/10.1109/TPAMI.2006.251
Status: Published
Refereed: Yes
URI: http://eprints.whiterose.ac.uk/id/eprint/1996

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