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Results for “color perception”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Toward the validation of crowdsourced experiments for lightness perception

Crowdsource platforms have been used to study a range of perceptual stimuli such as the graphical perception of scatterplots and various aspects of human color perception. Given the lack of control over a crowdsourced participant’s experimental setup, there are valid concerns on the use of crowdsourcing for color studies as the perception of the stimuli is highly dependent on the stimulus presentation. Here, we propose that the error due to a crowdsourced experimental design can be effectively averaged out because the crowdsourced experiment can be accommodated by the Thurstonian model as the convolution of two normal distributions, one that is perceptual in nature and one that captures the error due to variability in stimulus presentation. Based on this, we provide a mathematical estimate for the sample size needed to produce a crowdsourced experiment with the same power as the corresponding in-person study. We tested this claim by replicating a large-scale, crowdsourced study of human lightness perception with a diverse sample with a highly controlled, in-person study with a sample taken from psychology undergraduates. Our claim was supported by the replication of the results from the latter. These findings suggest that, with sufficient sample size, color vision studies may be completed online, giving access to a larger and more representative sample. With this framework at hand, experimentalists have the validation that choosing either many online participants or few in person participants will not sacrifice the impact of their results.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2022

The non-Riemannian nature of perceptual color space

Significance For over 100 y, the scientific community has adhered to a paradigm, introduced by Riemann and furthered by Helmholtz and Schrodinger, where perceptual color space is a three-dimensional Riemannian space. This implies that the distance between two colors is the length of the shortest path that connects them. We show that a Riemannian metric overestimates the perception of large color differences because large color differences are perceived as less than the sum of small differences. This effect, called diminishing returns, cannot exist in a Riemannian geometry. Consequently, we need to adapt how we model color differences, as the current standard, Δ E , recognized by the International Commission for Weights and Measures, does not account for diminishing returns in color difference perception.

Bujack, Roxana↗
DOE OSTI2025

Relative Contributions of sc-DER, mel-DER, Color Rendition, Chromaticity, and Illuminance to Spatial Brightness Perception

An experiment was conducted to examine spectrally based factors that contribute to the visual perception of interior environments, with a focus on brightness perception. Thirty-two participants evaluated 60 different lighting scenes in a mock office. The lighting spectral power distributions varied systematically in illuminance, chromaticity (CCT and Duv), s cone opic daylight efficacy ratio (sc-DER), melanopic daylight efficacy ratio (mel-DER), and color rendition (R f , R g , and R cs,h1 ). At the operationalized levels of these variables, illuminance had the largest effect on brightness perception. Notably, the second largest effect was due to changes in red chroma (R cs,h1 ). The effect of sc-DER was also statistically significant but was a tertiary effect. The effects of mel-DER, CCT, and Duv were not statistically significant. This large effect of red chroma is consistent with the existing understanding that changes in color perception are often perceived when illuminance changes. In conclusion, with appropriate changes in color rendition and other factors held constant, spatial brightness perception was preserved through a decrease from 500 lux to 250 lux.

42 ENGINEERING↗
DOE OSTI2021

Haze Mitigation in High-Resolution Satellite Imagery using Enhanced Style-Transfer Neural Network and Normalization Across Multiple GPUs

Despite recent advances in deep learning approaches, haze mitigation in large satellite images is still a challenging problem. Due to amorphous nature of haze, object detection or image segmentation approaches are not applicable. Also it is practically infeasible to obtain ground truths for training. Bounded memory capacity of GPUs is another constraint that limits the size of image to be processed. In this paper, we propose a style transfer based neural network approach to mitigate haze in a large overhead imagery. The network is trained without paired ground truths; further, perception loss is added to restore vivid colors, enhance contrast and minimize artifacts. The paper also illustrates our use of multiple GPUs in a collective way to produce a single coherent clear image where each GPU dehazes different portions of a large hazy image.

Park, Byung↗
DOE OSTI2020

The effect of lighting environment on task performance in buildings – A review

The effects of indoor environmental conditions on human health, satisfaction, and performance have been the focal point of research for decades. This paper reviews and summarizes the impact of lighting environment on task performance, specifically for the built environment audience. Existing studies included a variety of performance tests on cognitive performance and perception, visual acuity and reaction, memory, reasoning, and labor productivity. Illuminance, luminance ratio and correlated color temperature were found to affect performance in different ways, reflecting the impact of experimental techniques, conditions, performance evaluation methods used and data analysis methods. These were reviewed and categorized, with discussion on limitations related to sample size, modeling approach, carryover effects and other factors affecting individual differences in performance, with recommendations for future improvement. Although no universal conclusions can be made, in general, task performance seems to improve with higher illuminances, contrast ratios in the range of 7–11:1 (while always making sure that glare will not occur in the space) and higher correlated color temperature, while spectral tuning in the red or blue wavelengths has also shown positive effects. To obtain more generic evidence, future studies should be more consistent in terms of experimental procedures and overall light conditions, and also consider the effects of vertical illuminance, daylight provision/control, and outside views on task performance. Finally, studying performance with multi-factorial designs in a human-centered optimized manner (such as deploying variable lighting scenarios optimized for various tasks) can lead to deeper understanding of lighting effects on task performance, and ultimately to improved lighting design and operation in buildings overall.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2023

A Comparative Study of the Perceptual Sensitivity of Topological Visualizations to Feature Variations

Color maps are a commonly used visualization technique in which data are mapped to optical properties, e.g., color or opacity. Color maps, however, do not explicitly convey structures (e.g., positions and scale of features) within data. Topology-based visualizations reveal and explicitly communicate structures underlying data. Although our understanding of what types of features are captured by topological visualizations is good, our understanding of people's perception of those features is not. Further, this paper evaluates the sensitivity of topology-based isocontour, Reeb graph, and persistence diagram visualizations compared to a reference color map visualization for synthetically generated scalar fields on 2-manifold triangular meshes embedded in 3D. In particular, we built and ran a human-subject study that evaluated the perception of data features characterized by Gaussian signals and measured how effectively each visualization technique portrays variations of data features arising from the position and amplitude variation of a mixture of Gaussians. For positional feature variations, the results showed that only the Reeb graph visualization had high sensitivity. For amplitude feature variations, persistence diagrams and color maps demonstrated the highest sensitivity, whereas isocontours showed only weak sensitivity. These results take an important step toward understanding which topology-based tools are best for various data and task scenarios and their effectiveness in conveying topological variations as compared to conventional color mapping.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2022

Visually undistorted thin film electronic devices

Visually undistorted thin film electronic devices are provided. In one embodiment, a method for producing a thin-film electronic device comprises: opening a scribe in a stack of thin film material layers deposited on a substrate to define an active region and an inactive region of the thin-film electronic device, the stack comprising at least one active semiconductor layer. The active region comprises a non-scribed area of the stack and the inactive region comprises a region of the stack where thin film material was removed by the scribe. The method further comprises depositing at least one scribe fill material into a gap opened by the scribe. The scribe fill material has embedded therein one or more coloring elements that alter an optical characteristics spectrum of the inactive region to obtain an optical characteristics spectrum of the active region within a minimum perceptible difference for an industry defined standard observer.

Hammond, Scott R.↗
DOE OSTI2023

Visually undistorted thin film electronic devices

Visually undistorted thin film electronic devices are provided. In one embodiment, a method for producing a thin-film electronic device comprises: opening a scribe in a stack of thin film material layers deposited on a substrate to define an active region and an inactive region of the thin-film electronic device, the stack comprising at least one active semiconductor layer. The active region comprises a non-scribed area of the stack and the inactive region comprises a region of the stack where thin film material was removed by the scribe. The method further comprises depositing at least one scribe fill material into a gap opened by the scribe. The scribe fill material has embedded therein one or more coloring elements that alter an optical characteristics spectrum of the inactive region to obtain an optical characteristics spectrum of the active region within a minimum perceptible difference for an industry defined standard observer.

Hammond, Scott R.↗
DOE OSTI2024

Visually undistorted thin film electronic devices

Visually undistorted thin film electronic devices are provided. In one embodiment, a method for producing a thin-film electronic device comprises: opening a scribe in a stack of thin film material layers deposited on a substrate to define an active region and an inactive region of the thin-film electronic device, the stack comprising at least one active semiconductor layer. The active region comprises a non-scribed area of the stack and the inactive region comprises a region of the stack where thin film material was removed by the scribe. The method further comprises depositing at least one scribe fill material into a gap opened by the scribe. The scribe fill material has embedded therein one or more coloring elements that alter an optical characteristics spectrum of the inactive region to obtain an optical characteristics spectrum of the active region within a minimum perceptible difference for an industry defined standard observer.

Hammond, Scott R.↗
DOE OSTI2020

Examining Perceptions of Spanish Language Health Information Among Hispanics Living in the United States: A Qualitative Study Assessing Videos, Brochures, and Websites

Background Nationally, Hispanics experience health disparities manifested as a higher prevalence of chronic diseases in comparison to non-Hispanic Whites. Factors that influence health disparities in this population include inadequate dissemination of culturally and linguistically appropriate health information. Method Our qualitative analysis is based on data obtained from three focus groups with Spanish-speaking Hispanic adults conducted at a clinic in Nebraska. Participants were asked about their perceptions of health information in the form of videos, brochures, and websites. We followed the consolidated criteria for reporting qualitative research and used the theoretical framework of content analysis. Results For videos, attributes associated with higher levels of trust included a friendly health professional, the logo or name of a health care institute, and a reference specifying “se habla Español.” For brochures, attributes associated with trust included use of visual aids, use of numerous colors and big font sizes, the year of printing, and a health care agency logo. For websites, characteristics associated with trust were inclusion of plain language, use of pictures and videos, and date of last update. In all focus groups, participants perceived the use of mixed English/Spanish language in health information from pamphlets and websites as unprofessional. The use of unknown governmental logos in health promotional videos and websites was perceived as untrustworthy information. Conclusions Spanish-speaking Hispanics prefer health information supported by a health care agency or delivered by a health care professional. Health communication strategies should avoid the use of mixed English/Spanish language in sensitive information especially when combined with governmental logos.

De Alba Rosales, Armando↗