
Metamer mismatch bodies (MMBs) quantify the extent of metamer mismatching for a given color stimulus with a change in color mechanism (i.e. change in illuminant and/or observer). Prior work has shown that the MMB boundary can be efficiently approximated by spherical sampling of unit directions in the 6D joint color-mechanism space, and for each sampled direction, maximizing the boundary point subject to the metameric cross-section constraints. Many sampled directions map to the same boundary vertex, so the number of recovered vertices is typically far smaller than the number of sampled directions. This produces a plausible approximation, but the resulting boundary vertices, expressed in sensor-response spaces (for example XYZ, LMS, or RGB), are often distributed in a highly non-uniform manner. Increasing the number of sampled directions increases the number of recovered vertices but does not improve boundary uniformity. We explored a simple post-processing workflow that builds a larger candidate pool of vertices and then selects a fixed-size subset using a spacing-driven sampling algorithm, improving vertex uniformity as measured by a nearest-neighbor metric. This approach substantially improves vertex uniformity in sensor space, but it can discard boundary-defining extreme vertices, potentially altering hull volume and other distinguishing boundary features. We therefore argue that any practical workflow for improving MMB vertex uniformity should include an explicit mechanism for retaining boundary-critical extremes prior to applying spacing-driven selection.

Imagery from optical see-through (OST) head-mounted displays (HMDs) is perceived as a blending of light emitted by the display added to the light from the user’s physical environment, which can result in color distortions and desaturation of the virtual imagery. Due to these limitations, the user’s ability to distinguish between colors shown on the display may be reduced compared to more traditional types of displays, which may impact the interpretation of the symbology, and potentially reduce performance. Further, individual variation in color perception may also impact the utility of color symbology in OST HMDs. In this paper, we present a user study that investigates the utility of color-coded symbology displayed on an OST Augmented Reality (AR) display within a flight simulator. We compare performance between participants with normal color vision and participants with color vision deficiencies in a dynamic flight simulator and investigate effects of symbology contrast and symbology color set on participant response times, accuracy, and eye behavior. Our results suggest that for the color sets tested, increasing the size of the set beyond a monochrome color results in reduced performance for both color normal and color deficient subjects. It’s possible that custom color sets specific to OST displays are needed to achieve performance benefits.

Tinted eyewear acts as a wavelength-dependent spectral filter in the visual chain and can alter both perceived color appearance and color discrimination, yet its perceptual impact is typically assessed only through physical transmittance or task-specific criteria. This paper proposes a theoretical and computational framework for evaluating tinted eyewear by integrating spectral transmittance with illumination spectra and luminance level. Color appearance changes are predicted using CIECAM16 attributes and bin-based gamut visualizations derived from the TM-30 Color Evaluation Samples, while discrimination performance is assessed for both small and large color differences and validated against behavioral data from two psychophysical experiments. Comparisons among CAM16-UCS color differences, CIEDE2000, HyAB, and cone-contrast metrics show that appearance-based measures effectively describe global color appearance changes, whereas cone-contrast–based metrics exhibit the strongest correspondence with behavioral discrimination performance. The framework provides a perceptually grounded basis for evaluating and comparing tinted eyewear across applications where both color appearance and visual performance are critical.

Tinted eyewear alters the spectral information reaching the human eye, potentially influencing visual performance in real-world tasks. Our previous work quantified changes in color discrimination ability under tinted eyewear using a psychophysical experiment. The present study extends this investigation by employing a visual search method to evaluate perceptual sensitivity. Two psychophysical experiments were conducted to evaluate visual performance under tinted eyewear: one focused on small color difference, assessed by reaction time and accuracy of target detection, and the other on large color differences, evaluating discrimination ability with increasing viewing distance. Overall, the results suggest that color appearance–based evaluations may help account for variations in task performance under tinted eyewear, particularly for small color difference stimuli. For large color difference stimuli, performance difference caused by tinted eyewear were observed, but the relationship between prediction and performance was not clear, which needs future investigation. By comparing the experimental data with model predictions, this study aims to provide a deeper understanding of the perceptual behavior changes caused by tinted eyewear.

Tinted eyewear is increasingly utilized in outdoor environments to protect against ultraviolet radiation and manage luminance levels reaching the human visual system. While these protective functions are well-established, these modifications can also affect color perception. This research investigates how different tinted eyewear affects observers’ ability to distinguish small color differences in reflective samples, with implications for understanding how specific eyewear transmittance properties influence color discrimination ability in different environments. Two sets of stimuli are used: (1) six adjacent Munsell sample pairs varying only in hue, and (2) seven parameric pairs generated through Kubelka-Munk theory modeling of 16 pigments. Six eyewear with different transmittance properties were examined in this study under normalized lighting conditions. Color differences (ΔE2000) were predicted using spectral data and validated through psychophysical experiments with 27 observers using a scaling method. Results demonstrate that tinted eyewear can alter color discrimination ability compared to neutral eyewear, with effects varying based on the interaction between the eyewear’s spectral transmittance and the stimuli’s spectral reflectance. For example, one foliage pair showed a ΔE2000 of 2.37 under neutral eyewear that increased to 5.21 under a tinted eyewear, with corresponding mean observed visual differences of 2.79 and 5.51, respectively. Overall, the observed color difference evaluations aligned with predictions, with correlation coefficients (r) of 0.816. This research enhances the understanding of how tinted eyewear affects color perception and supports the development of eyewear optimized for specific outdoor environments.

Color accuracy is essential in digital imaging for Cultural Heritage when reproducing an object into digital format. As a practitioner in the field, curiosity rose as to what the long-term effects are of working in a low-light environment after chronic fatigue and strained eyes became the daily norm. Multiple literatures were reviewed to extract the groundwork of color vision in low light and what achieves proper and consistent information processing; however, there were no known specific studies for the impetus for this topic. This research aims to explore color vision in low light to recognize potential short- and long-term physiological vision changes. Studies uncovered multiple variables impact human vision when processing an image or scene. This paper investigates the structure of the eye by comparing human vision to the structure of a camera system, the processing of color in the retina, the recommended viewing environment for cultural heritage capture, different conditions that impact perception, and solutions for regular eye maintenance. As is often said, awareness is the first step to prevention.

It is necessary to avoid using of confusion colors of dichromats in order to mediate information defined by color in visual materials to anyone. Such a color design method is called color universal design. Dichromatic simulators have been widely used for the color universal design. Recently, a new color universal design method without a dichromatic simulator has been proposed. Yoshitake et al. made a color sample set for the new color universal design method by the Natural Color System chips containing 1948 colors. We designed a campus map using their sample set in a campus barrierfree design project at Kyushu University. We show the results of the Kyushu University barrier-free design project.