We design an algorithm based on illuminant invariance theory to find shadow regions in a colour image. Shadows are caused by a local change in both the colour and the intensity of illumination. Using both chromaticity and intensity cues, an illuminant discontinuity measure is derived by which shadow edges can be locally identified. We model the problem of finding shadows by a Markov Random Fiel...

Many professional women educators make the transition from school settings to academe after significant graduate work in their field(s). This transition, which often occurs on a mid- late-career trajectory, places such individuals within liminal spaces many levels as they inevitably must navigate unfamiliar, alien, territory that frequently does not recognize or respect experiences with enter n...

Physically accurate soft shadows in 3D applications can be simulated by taking multiple samples from all over the area light source and accumulating them. Due to the unpredictability of the size of the penumbra regions, the required sampling density has to be high in order to guarantee smooth shadow transitions in all cases. Hence, several hundreds of shadow maps have to be evaluated in any sce...

Todays graphics hardware is capable of performing a large number of operations at very high rates. Since most of the graphics chips are designed in a pipelined fashion, e.g. similar to the OpenGL rendering pipeline, it is necessary to utilize as many processing units as possible to achieve high-quality results while keeping the number of rendering passes needed at a minimum. In this paper we pr...

We investigate the brightness distribution in and around outdoor shadows (for a variety of sky conditions) using modeling and field measurements. The dominant factor influencing the brightness of a shadow is the solid angle subtended by the object blocking the Sun. Occulters at the zenith that subtend a small solid angle cast shadows that are bright and possess a nearly uniform brightness acros...

Shadows are crucial for enhancing realism and provide important visual cues for many applications. This can be beneficial for the purposes like revealing information about the object’s shape, orientation, size, position, intensity, physical characteristics of the screen and even about the light source, type and behavior of shadowed surfaces. In recent years, many interesting contributions have ...