Psychophysics of Night Vision Device halos

Robert S. Allison, Tracey Brandwood, Margarita Vinnikov, James E. Zacher, Sion Jennings, Todd Macuda, Paul Thomas, Stephen A. Palmisano

Research output: Chapter in Book/Report/Conference proceedingChapter

3 Scopus citations


In modern Night Vision Devices (NVDs) 'halo' around bright light sources remains a salient imaging artifact. Although a common feature of image intensified imagery, little is known of the perceptual and operational effects of this device limitation. This paper describes two related sets of experiments. In the first set of experiments, we provide quantitative measurements of Night Vision Device (NVD) halos formed by light sources as a function of intensity and distance. This characterization allows for analysis of the possible effects of halo on human perception through NVDs. In the second set of experiments, the effects of halation on the perception of depth and environmental layout are investigated psychophysically. The custom simulation environment used and results from psychophysical experiments designed to analyze halo-induced errors in slope estimation are presented. Accurate simulation of image intensifier physics and NVD scene modeling is challenging and computationally demanding, yet needs to be performed in real-time at high frame rates and at high-resolution in advanced military simulators. Given the constraints of the real-time simulation, it is important to understand how NVD artifacts impact task performance in order to make rational engineering decisions about the required level of fidelity of the NVD simulation. A salient artifact of NVD viewing is halo, the phenomenon where the image of a bright light source appears surrounded by disc-like halo. High-fidelity physical modeling of these halo phenomena would be computationally expensive. To evaluate the level of approximation that would be sufficient for training purposes human factors data is required. NVD halos generated by light sources in a scene have a size that is approximately invariant with intensity and distance. Objective and subjective measures of halo geometry indicate that halo size, when halo is present, is relatively invariant of target distance or intensity. This property results in perceptual distortions and strong illusions with isolated stimuli. In complex scenes, systematic distortions of slant are predicted due to an imposed texture gradient created by the halo. We investigated this hypothesis in psychophysical experiments. The results suggest that perception of slant and glideslope in complex scenes is remarkably tolerant of texture gradients imposed by NVG halo. These results are discussed in terms of NVG simulation and of the ability of human operators to compensate for perceptual distortions.

Original languageEnglish (US)
Title of host publicationVision and Displays for Military and Security Applications
Subtitle of host publicationThe Advanced Deployable Day/Night Simulation Project
PublisherSpringer New York
Number of pages18
ISBN (Print)9781441917225
StatePublished - 2010
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy


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