Title

Shape from intensity gradient

Authors

Authors

R. Zhang;M. Shah

Comments

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Abbreviated Journal Title

IEEE Trans. Syst. Man Cybern. Paart A-Syst. Hum.

Keywords

intensity gradient; multigrid technique; physics-based vision; shape-from-shading; SURFACE; Computer Science, Cybernetics; Computer Science, Theory & Methods

Abstract

Unlike existing global shape-from-shading (SFS) algorithms which involve the brightness constraint in their formulation, we propose a new SFS algorithm which replaces the brightness constraint with an intensity gradient constraint. This is a global approach which obtains the solution by the minimization of an error function over the entire image. Through the linearization of the gradient of the reflectance map and the discretization of the surface gradient, the intensity gradient can be expressed as a linear function of the surface height. A quadratic error function, which involves the intensity gradient constraint and the traditional smoothness constraint, is minimized efficiently by solving a sparse linear system using the multigrid technique. Neither the information at singular points nor the information at occluding boundaries is needed for the initialization of the height. Results for real images are presented to show the robustness of the algorithm, and the execution time is demonstrated to prove its efficiency.

Journal Title

Ieee Transactions on Systems Man and Cybernetics Part a-Systems and Humans

Volume

29

Issue/Number

3

Publication Date

1-1-1999

Document Type

Article

Language

English

First Page

318

Last Page

325

WOS Identifier

WOS:000079909700009

ISSN

1083-4427

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