Visual saliency of urban objects at night: Impact of the density of background light patterns

As with other types of visual design, lighting design considers the relationship between objects and their context. With outdoor lighting design it is relevant to consider how background lighting might influence the perception of urban objects, and thus influence lighting design decisions. Previous studies have shown that salience is strongly influenced by visual context: the same target may or may not be salient, depending on how it is embedded in a scene. Experimental work was carried out to determine the impact of background density of lighting patterns on the visual saliency of the target and also interaction between the density of light patterns and luminance contrast in object saliency. The result shows that the visual saliency of illuminated urban objects is significantly reduced by increasing the density of background light pattern.