Perceptually Based Afterimage Synthesis

Abstract

Afterimages comprise a common, recurring perceptual phenomenon experienced in a daily-basis. Afterimages are best realized when staring at some high intensity light source (i.e., a light bulb) and then shifting the ocular focus to other less luminous portions of the scene: a temporary “ghost” image of that strong intensity remains imprinted on the retina. During the time the afterimage stays active, several exquisite color gradations appear and fade. Although research on the topic has been moderately active in ophthalmology and vision domains, no definitive model has been devised. Furthermore, no afterimage simulation seems to have yet been investigated in computer graphics. In this paper we attempt to introduce the topic to the field and therefore widen the research spectrum of computer graphics. The proposed technique is based on psychophysical and physiological evidence, addressing the color transitions and the duration of the effect. The method is also fast and suitable for real-time applications. Our stance towards afterimages is more than just curiosity on this peculiar effect: we believe that its understanding and proper simulation can assist on relevant tasks such as urban and road engineering for safer pedestrian and vehicle mobility at adverse lighting conditions.