Conspicuity and identifiability: efficient calibration tools for synthetic imagery

Abstract

We argue that visual conspicuity and identifiability are two efficient task-related measures that can be deployed to calibrate synthetic imagery that is intended to be used for human visual search and detection tasks. The conspicuity of a target is operationally defined as the region around the center of the visual field where the target is capable to attract visual attention. Visual conspicuity predicts human visual search performance in realistic and military relevant complex scenario's. Conspicuity can easily and quickly be measured either in the field (in complex environments) or in the lab. This eliminates the need for costly and time consuming visual search experiments. The agreement between field and lab measurements implies that conspicuity can be used to validate synthetic imagery. Target identifiability is operationally defined as the amount of Gaussian blur that is required to reduce the target signature to its identification threshold. It is an efficient metric that can be used to gain insight into human identification performance without having to resort to elaborate and costly experiments. Identifiability is directly related to PID-performance, and is therefore well suited for comparing synthetic and realistic imagery. We conclude that synthetic imagery can be calibrated for human visual search and detection tasks by setting the conspicuity and identifiability of targets equal to those of their real world counterparts.