In this paper a face recognition system that is based on illumination subspaces is presented. In this system, first, the dominant illumination directions are learned using a clustering algorithm. Three main illumination directions are observed: Ones that have frontal illumination, illumination from left and right sides. After determining the dominant illumination direction classes, the face spa...

While computer vision systems often assume simple illumination models, real-world illumination is highly complex, consisting of reflected light from every direction as well as distributed and localized primary light sources. One can capture the illumination incident at a point in the real world from every direction photographically using a spherical illumination map. This paper illustrates, thr...

an 8-year-old female japanese spitz dog was reffered to shiraz university veterinary clinic, with signof anisocoria. clinical examinations revealed mydriasis in the right eye. ocular examination revealed adilated and unresponsive right pupil to focal illumination. by testing with topical 2% pilocarpine, thetentative diagnosis was parasympathetic denervation of the right iris sphincter muscle—pu...

In this paper we show how tools from group theory can be used to find invariants for time-changing illumination changes. In the first part of the paper we give a brief overview over the theory of one-parameter groups and their invariants. In the second part we describe how the chromaticity coordinates of time-changing illumination spectra can be described by one-parameter curves. Examples for b...

Captured images arise through interaction between objects of interest and illuminating light sources. If the latter are unevenly distributed, or are too strong or too weak, the image can have low contrast either locally or globally, impeding its interpretation and reducing its usefulness. In practice, control of illumination conditions is challenging, and not always possible. Thus, we propose a...