Adapting Michelson Contrast for Use with Optical See-Through Displays

Due to the additive light model employed by current optical see-through head-mounted displays (OST-HMDs), the perceived contrast of displayed imagery is reduced with increased environment lumi-nance, often to the point where it becomes difficult for the user to accurately distinguish the presence of visual imagery. While existing contrast models, such as Weber contrast and Michelson contrast, can be used to predict when the observer will experience difficulty distinguishing and interpreting stimuli on traditional dis-plays, these models must be adapted for use with additive displays. In this paper, we present a simplified model of luminance contrast for optical see-through displays derived from Michelson's contrast equation and demonstrate two applications of the model: informing design decisions involving the color of virtual imagery and optimizing environment light attenuation through the use of neutral density filters.