منابع مشابه
Effect of Different Illumination Sources on Reading and Visual Performance
Purpose To investigate visual performance during reading under different illumination sources. Methods This experimental quantitative study included 40 (20 females and 20 males) emmetropic participants with no history of ocular pathology. The participants were randomly assigned to read a near visual task under four different illuminations (400-lux constant): compact fluorescent light (CFL), t...
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The effects of varying the silica source on synthesis of NaX zeolite crystals via conventional hydrothermal method have been investigated. Five different silica sources were selected while other parameters like Al source, reaction and aging time, SiO2/Al2O3 molar ratio and temperature were same. The prepared products were characterized by XRD technique. The results showed that different cry...
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We present a new theory that shows that two images of the same object taken under two different light directions can be made virtually identical by filtering each image by a directional derivative filter. The direction and magnitude of the derivative is generally different for each image, and depends on illumination directions used. The method requires the object surface to be of uniform Lamber...
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To deal with image variations due to illumination problem, recently Ramamoorthi and Basri have independently derived a spherical harmonic analysis for the Lambertian reflectance and linear subspace. Their theoretical work provided a new approach for face representation, however both of them had the assumption that the 3D surface normal and albedo are known. This assumption limits this algorithm...
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ژورنال
عنوان ژورنال: Nature
سال: 1883
ISSN: 0028-0836,1476-4687
DOI: 10.1038/028343c0