Title
Perspective Shape from Shading: Ambiguity Analysis and Numerical Approximations
Abstract
In this paper we study a perspective model for shape from shading and its numerical approximation. We show that an ambiguity still persists, although the model with light attenuation factor has previously been shown to be well-posed under appropriate assumptions. Analytical results revealing the ambiguity are complemented by various numerical tests. Moreover, we present convergence results for two iterative approximation schemes. The first is based on a finite difference discretization, whereas the second is based on a semi-Lagrangian discretization. The convergence results are obtained in the general framework of viscosity solutions of the underlying partial differential equation. In addition to these theoretical and numerical results, we propose an algorithm for reconstructing discontinuous surfaces, making it possible to obtain results of reasonable quality even for complex scenes. To this end, we solve the constituting equation on a previously segmented input image, using state constraint boundary conditions at the segment borders.
Year
DOI
Venue
2012
10.1137/100815104
SIAM J. Imaging Sciences
Keywords
Field
DocType
underlying partial differential equation,ambiguity analysis,various numerical test,perspective shape,semi-lagrangian discretization,numerical approximation,numerical result,finite difference discretization,constituting equation,convergence result,numerical approximations,perspective model,iterative approximation scheme,shape from shading,finite difference methods
Convergence (routing),Discretization,Boundary value problem,Mathematical optimization,Mathematical analysis,Viscosity,Finite difference method,Ambiguity,Partial differential equation,Photometric stereo,Mathematics
Journal
Volume
Issue
ISSN
5
1
1936-4954
Citations 
PageRank 
References 
14
0.71
22
Authors
5
Name
Order
Citations
PageRank
Michael Breuß116825.45
Emiliano Cristiani213212.58
Jean-Denis Durou327320.42
Maurizio Falcone423519.89
Oliver Vogel59510.68