<title>Influence of spatial luminance interactions on perceived brightness</title>

Abstract

Most color appearance models that have been published so far require a simplified description of the viewing field which is subdivided into a small number of homogeneous regions. The tristimulus values and luminance levels of these regions serve as input parameters for the models. The purpose of this paper however is to study brightness perception in a complex, achromatic surround using a more detailed description of the entire viewing field. Therefore, a number of psycho physical experiments were carried out using a CRT display on which relatively complex images were presented. Several observers were asked to judge the perceived brightness by adjusting the luminance level of a reference grey for a perfect brightness match. All thereby obtained psycho physical data were used to develop a new brightness appearance model that takes all objects in the entire visual field into account. The model includes an object feature extraction stage, in which object properties like area and position are extracted, a stage in which the characteristic object data are sorted into the appropriate classes of a histogram and a multivariate map in the form of a feedforward neural network to calculate the prediction of the perceived brightness.