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Proceedings Paper

Spline-Based Algorithms For Shape From Shading
Author(s): Rui J.P. de Figueiredo; Vishal Markandey
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Paper Abstract

Algorithms to recover the shape of objects from the shading caused by illumination are reported. This constitutes an approach dif-ferent from the variational method using occluding boundaries found in the literature. The latter method determines a surface that satisfies the image irradiance equation as a constrained optimization problem, where occluding boundaries of the object's silhouette provide initial conditions and the image irradiance equation, and smoothness constraints determine an objective function to be minimized. Our technique splits the problem into two subproblems. The first subproblem consists of determining the surface function values on a two-dimensional grid of points from the corresponding image irradiance values that are measured. These points are determined by minimizing the square error between the irradiance values and the surface reflectance at the corresponding points determined from the reflectance map. The second subproblem consists of fitting a two-dimensional spline surface to the surface points computed from the above grid, using smoothing criteria based on appropriate partial different operators. Depending on the criterion chosen, different types of spline fits for the surface may be obtained.

Paper Details

Date Published: 12 March 1988
PDF: 4 pages
Proc. SPIE 0850, Optics, Illumination, and Image Sensing for Machine Vision II, (12 March 1988); doi: 10.1117/12.942872
Show Author Affiliations
Rui J.P. de Figueiredo, IEEE (United States)
Vishal Markandey, Rice University (United States)

Published in SPIE Proceedings Vol. 0850:
Optics, Illumination, and Image Sensing for Machine Vision II
Donald J. Svetkoff, Editor(s)

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