Sky is among the subject matters frequently seen in photographs and useful for image understanding, processing, and retrieval. We propose a novel approach to sky detection based on color classification, region extraction, and physicsmotivated sky signature validation. First, the color classification is performed to generate a belief map of sky colored pixels. Next, connected components are extr...

In Computer Vision, the sky color is used for lighting correction, image color enhancement, horizon alignment, image indexing, and outdoor image classification and in many other applications. In this article, for robust color based sky segmentation and detection, usage of lighting correction for sky color detection is investigated. As such, the impact of color constancy on sky color detection a...

The Aladin interactive sky atlas, developed at CDS, is a service providing simultaneous access to digitized images of the sky, astronomical catalogues, and databases. The driving motivation is to facilitate direct, visual comparison of observational data at any wavelength with images of the optical sky, and with reference catalogues. The set of available sky images consists of the STScI Digitiz...

Urban morphology, including buildings’ typology and their configuration, affects sky view factor and insolation, which are two of the most influential parameters in urban microclimate. These become even more important in extreme environmental conditions. In this research, challenge was to generate various rule based urban morphologies in a parametric environment. Then, to evaluate them based on...

“The most urgent problem facing the newly independent United States was how to pay for the war that won the country its freedom; America’s debt was enormous. Its greatest asset was the land west of the Ohio River, but for this huge territory to be sold, it had first to be surveyed—that is, measured out and mapped. And before that could be done, a uniform set of measurements had to be chosen for...

Sky models are quantitative representations of natural luminance of the sky under various atmospheric conditions. They have been used extensively in studies of architectural design for nearly a century, and more recently for rendering objects in the field of computer graphics. The objectives of this paper are to (a) describe sky models, (b) demonstrate how map designers can render terrain under...

In this paper, an extension to the radiosity method, for the simulation of daylight, is presented. The sky hemisphere around the scene is subdivided into a set of sky patches. By defining a location on the earth, a time of day and the weather conditions (e.g., clear sky, overcast, partly cloudy) a sky model (e.g., CIE or Perez) is applied to compute the radiosity values for each sky patch. In a...