Title

Shape from shading with variable albedo

Authors

Authors

P. S. Tsai;M. Shah

Comments

Authors: contact us about adding a copy of your work at STARS@ucf.edu

Abbreviated Journal Title

Opt. Eng.

Keywords

physics-based vision; shape-from-shading; albedo estimate; Optics

Abstract

Most traditional shape-from-shading algorithms assume that an image contains only a single object with Lambertian surface and uniform albedo values. These algorithms perform poorly on images with nonuniform albedo values. In this paper, we first discuss a linear shape-from-shading method that employs discrete approximations for the surface normal using finite differences of the depth and linearizes the reflectance function in depth directly. Next we present a simple method to cancel the effect of albedo variation. In our approach, we first estimate the albedo values for each pixel, and segment the scene into regions with uniform albedo values. However, the estimated albedo values are not accurate at the points near edges, so we apply a modified median filter to improve the result. Then we adjust the intensity value for each pixel by dividing by the corresponding albedo value before applying the linear shape-from-shading method. Experimental results are presented for several synthetic and actual images. (C) 1998 Society of Photo-Optical Instrumentation Engineers.

Journal Title

Optical Engineering

Volume

37

Issue/Number

4

Publication Date

1-1-1998

Document Type

Article

Language

English

First Page

1212

Last Page

1220

WOS Identifier

WOS:000072995200021

ISSN

0091-3286

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