Abstract :
Objective: We sought to determine the joint influence of resolution, target range, and image contrast on the detection and identification of targets in simulated naturalistic scenes. Background: Resolution requirements for target acquisition have been developed based on threshold values obtained using imaging systems, when target range was fixed, and image characteristics were determined by the system. Subsequent work has examined the influence of factors like target range and image contrast on target acquisition. Method: We varied the resolution and contrast of static images in two experiments. Participants (soldiers) decided whether a human target was located in the scene (detection task) or whether a target was friendly or hostile (identification task). Target range was also varied (50-400 m). In Experiment 1, 30 participants saw color images with a single target exemplar. In Experiment 2, another 30 participants saw monochrome images containing different target exemplars. Results: The effects of target range and image contrast were qualitatively different above and below 6 pixels per meter of target for both tasks in both experiments. Conclusion: Target detection and identification performance were a joint function of image resolution, range, and contrast for both color and monochrome images. Application: The beneficial effects of increasing resolution for target acquisition performance are greater for closer (larger) targets. Keywords: sensory and perceptual processes, vision, displays DOI: 10.1177/0018720818760331