Visual detection with search: an empirical model

A visual detection model, including search, is constructed from empirical data on foveal and off-axis contrast thresholds, fixation times, saccadic sizes, and eye response times. The model includes one parameter to account for scene complexity and human preparedness, and its accounts quantitatively for the effects of clutter on this parameter and on other variables. The resulting algorithm correlates well with published laboratory results at light levels of 1 fL or more also gives intuitively satisfying predictions of field performance