Abstract | ||
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In classical photometric stereo, a Lambertian surface is illuminated from multiple distant point light-sources. In the present paper we consider nearby light sources instead, so that the unknown surface, is illuminated by non-parallel beams of light. In continuous noiseless cases, the recovery of a I.,ambertian surface from non-distant illuminations, reduces to solving a system of non-linear partial differential equations for a bivariate function it, whose graph is the visible part of the surface. This system is more difficult to analyse than its counterpart, where light-sources are at infinity. We consider here a similar task, but with slightly more realistic assumptions: the photographic images are discrete and contaminated by Gaussian noise. This leads to a non-quadratic optimization problem involving a large number of independent variables. The latter imposes a heavy computational burden (due to the large matrices involved) for standard optimization schemes. We test here a feasible alternative: an iterative scheme called 2-dimensional Leap-Frog Algorithm(14). For this we describe an implementation for three light-sources in sufficient detail to permit code to be written. Then we give examples verifying experimentally the performance of Leap-Frog. |
Year | DOI | Venue |
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2004 | 10.1007/1-4020-4179-9_16 | COMPUTER VISION AND GRAPHICS (ICCVG 2004) |
Keywords | Field | DocType |
photometric stereo, non-quadratic optimization, noise reduction | Noise reduction,Computer vision,Infinity,Algorithm,Artificial intelligence,Variables,Bivariate analysis,Gaussian noise,Partial differential equation,Optimization problem,Photometric stereo,Mathematics | Conference |
Volume | Citations | PageRank |
32 | 6 | 0.52 |
References | Authors | |
12 | 2 |
Name | Order | Citations | PageRank |
---|---|---|---|
Ryszard Kozera | 1 | 163 | 26.54 |
Lyle Noakes | 2 | 149 | 22.67 |