CONICET | Buscador de Institutos y Recursos Humanos

Based on the experimental visual data obtained for self-luminous stimuli surrounded by a dark background, a new colour appearance model (CAM) for unrelated self-luminous stimuli, CAM15u, was previously developed. To extend the model to related selfluminous stimuli, the colour appearance of coloured self-luminous stimuli surrounded by a luminous background was evaluated using the magnitude estimation method.Experiments have been performed in Belgium and in Argentina using two differentexperimental setups. With a LED setup in the Belgian laboratory, visual data on the perception of brightness, hue and amount of white of 30 coloured self-luminous stimuli surrounded by a luminous background were collected. Luminance levels of the stimuli and the background were respectively 50 cd/m² and 28 cd/m² (positive contrast condition). With a projector setup in the Argentinian laboratory, visual data on the perception of brightness and amount of white of 32 coloured self-luminous stimuli surrounded by a luminous background were collected. Luminance levels of the stimuli and the background were respectively 10 cd/m² and 5.6 cd/m² (positive contrast condition). For both experiments; the brightness scaling shows a clear and prominent HelmholtzKohlrausch effect. This effect describes the impact of the saturation of a stimulus on the perceived brightness and has been seriously underestimated in earlier CAMs. Bothbrightness, hue and amount of white are found to be well predicted by CAM15u, for this positive contrast condition.