Using Vision Modeling to Define Occupational Vision Standards

Abstract

A methodology is introduced to assist in the construction of performance-based occupational vision standards. A simple image discrimination model is first calibrated using stimuli representative of airframe and powerplant cracks. It is then used to predict simulated crack visibility for cracks of different lengths and widths. Visual acuity declines are simulated using a Gaussian blur function on the crack images. Crack width is shown to be a salient cue for crack detection. This modeling technique can generate the data necessary to construct empirically-based occupational vision standards. Future research will validate model predictions with human psychophysical data.

8.3: Visual Modeling of Upscaled Image Discrimination

“…Images were presented on a 1920x1080 37" display with viewing distances of 2H, 4H and 6H for a 1080p display, corresponding to 1H, 2H, and 3H for a 4K display. Observers controlled the adjusted image via a blending weight according to Eqn (1) and similar to [11]. At a weight w=0 the adjusted image was maximally different from the reference image while at weight w=1 the adjusted and reference images were identical.…”