General illumination using LEDs has enabled designers to have precise control of the intensity and color of an illuminated area. In this work, I investigate how these systems can dynamically adjust to create optimal lighting conditions in the built environment. By incorporating environmental feedback into a system control loop, i.e., illuminance or luminance measurements, the precise intensity ...

Colour cues were used to obtain robust detection and tracking of people in relatively unconstrained dynamic scenes. Gaussian mixture models were used to estimate probability densities of colour for skin, clothing and background. These models were used to detect, track and segment people, faces and hands. A technique for dynamically updating the models to accommodate changes in apparent colour d...

Industrial lighting covers a wide range of different characteristics of working interiors and work tasks. This study investigated the effects of illumination on visual workload in visual display terminal (VDT) workstation. Ten college students (5 males and 5 females) were recruited as participants to perform VDT signal detection tasks. A randomized block design was utilized with four light colo...

Pose and illumination variations remain a persistent challenge in face recognition. In this paper, we present a framework for face recognition from video sequences that is robust to large changes in facial pose and lighting conditions. Our method is based on a recently obtained theoretical result that can integrate the effects of motion, lighting and shape in generating an image using a perspec...

Background elimination models are widely used in motion tracking systems. Our aim is to develop a system that performs reliably under adverse lighting conditions. In particular, this includes indoor scenes lit partly or entirely by diffuse natural light. We present a modified “median value” model in which the detection threshold adapts to global changes in illumination. The responses of several...

Goldfish (Carassius auratus) were reared from hatching in constant light (340 lux), cyclic light (12 hr 320 lux, 12 hr dark) or constant dark. Absolute visual threshold was determined psychophysically in animals that still responded to visual stimuli after 1-3 years of exposure, by means of a classically conditioned respiration suppression technique wherein animals were presented with different...

Display devices, more than ever, are finding their ways into electronic consumer goods as a result of recent trends in providing more functionality and user interaction. Combined with the new developments in display technology towards higher reproducible luminance range, the mobility and variation in capability of display devices are constantly increasing. Consequently, in real life usage it is...

Photoinduced alterations of light-sensitive artifacts represent one of the main problems that conservators and curators have to face for environmental control in museums and galleries. Therefore, increasing attention has been recently devoted to developing strategies of indoor light monitoring, especially aimed at minimizing the cumulated light exposure for the objects on exhibit. In this work ...

Statistical active contour models (aka statistical pressure snakes) have attractive properties for use in mobile manipulation platforms as both a method for use in visual servoing and as a natural component of a human-computer interface. Unfortunately, the constantly changing illumination expected in outdoor environments presents problems for statistical pressure snakes and for their image grad...