We propose a new method for classification of photometric factors, such as diffuse reflection, specular reflection, attached shadow, and cast shadow. For analyzing real images, we utilize the photometric linearization method which was originally proposed for image synthesis. First, we show that each pixel can be photometrically classified by the simple comparison of the pixel intensity. Our cla...

The interaction of light with surfaces creates complex lighting effects that provide potentially useful information about the spatial relationships between objects. Previous research has shown cast shadows to be effective in determining the 3D layout of a scene. Interreflections are another source of information for spatial relationships; these, however, have been largely ignored in studies of ...

Solar radiation data are available for many locations on an hourly basis. Simulation studies of solar energy systems have generally used these hourly values to estimate longterm annual performance, although solar radiation can exhibit wide variations during an hour. Variations in solar radiation during an hour, such as on a minute basis, could result in inaccurate performance estimates for some...

This theory was originally developed for paint films but works quite well in many circumstances for paper. It is not, however, terribly good for dyed papers (or very dark, unbleached papers) when light absorption reaches a high level. A limiting assumption is that the particles making up the layer must be much smaller than the total thickness. Both absorbing and scattering media must be uniform...

We present a comprehensive overview of the occurrence of discrete and diffuse aurora in the nightside Northern Hemisphere at invariant latitudes 55−75. Twenty-one months of Freja observations (1 January 1993 to 30 September 1994) from the Northern Hemisphere, obtained at ∼1700 km altitude, are included in this investigation. We investigate the importance of seasonal effects, solar illumination ...

Abstract--Measurements of cloudiness and of global, direct, and diffuse radiation taken over a 13 mo period at Davis, CA, are analyzed in terms of global transmission (K0 and diffuse fraction (Kd) for clear sky conditions and for various cloudiness conditions. A number of global transmission clear sky models are compared with observations for ranges of total water column and turbidity and some ...

Existing radiometric compensation methods are based on the assumption that the projection surface (screen) is Lambertian, i.e. there exists no specular reflection. Thus the methods cannot be applied to non-Lambertian surfaces which are ubiquitous in our everyday environment. In this paper, we try to faithfully display an image onto non-Lambertian surfaces using multiple overlapping projectors a...

We present a method to construct 3D angle gathers from extended images obtained using wave-equation migration. The method relies on an analytic formula that associates the reflection and azimuth angle to reflection kinematics in the images. The decomposition is able to render the angle gathers that characterize the reflectivity as a function of both reflection and azimuth angle simultaneously. ...

The stationary Boltzmann equation for hard and soft forces in the context of a two component gas is considered in the slab when the molecular masses of the 2 component are different. An L existence theorem is proved when one component satisfies a given indata profile and the other component satisfies diffuse reflection at the boundaries. Weak L compactness is extracted from the control of the e...