Color Contrast Research Articles

Accessibility of United States ophthalmology hospital webpages to people with visual disabilities

PurposeEnhancing the accessibility of ophthalmology webpages can help individuals with vision access needs obtain essential appointment information, educational resources, and available ophthalmic services. This study evaluated the accessibility of these webpages for patients with visual impairment and color vision deficiencies. DesignRetrospective cross-sectional study. MethodsIn February 2024, the Web Content Accessibility Guidelines 2.0 (WCAG 2.0) were used to assess the accessibility of the web homepages of the top-ranked ophthalmology institutes in the United States using three evaluation tools: AChecker, ARC Toolkit, and WAVE. The webpages of the 38 top-ranked hospitals for ophthalmology in the 2023 US News & World Report were evaluated. ResultsAll assessed ophthalmology hospital and institute webpages had accessibility issues. The issues identified by each tool significantly impeded webpage navigation, with the mean number of issues as follows: AChecker (13.08, SD = 14.51), ARC Toolkit (16.21, SD = 17.68), and WAVE (6.47, SD = 7.14). The mean number of color contrast issues per website was 10.18 (SD = 15.84), present in 87 % (33/38) of the websites assessed. Most issues made information and interface components difficult to perceive (297/497, 59.76 %), and websites difficult to navigate or operate (145/497, 29.18 %). Common issues affecting people who are blind or have low vision and rely on screen readers included the absence of alternative text for images, hyperlinks without destination information, and missing instructions for user data input (e.g., search bars). ConclusionsOphthalmology webpages should be revised to comply with WCAG guidelines to improve accessibility for people with vision access needs. Addressing these issues can reduce information inequities for patients with visual disabilities and enhance their understanding of clinical processes, treatment, care plans, and available services such as transportation and online support groups.

Color Characteristics of High Yttrium Oxide–Doped Monochrome and Multilayer Partially Stabilized Zirconia upon Different Sintering Parameters

Abstract Objectives Sintering influences the optical properties of zirconia. This study examined the effect of altering sintering temperature and time of monochrome (Mo) and multilayer (Mu) 5 mol% yttria-partially stabilized zirconia (5Y-PSZ) on color characteristics. Materials and Methods Three hundred specimens (width × length × thickness = 10 × 20 × 2 mm) were prepared from Mo and Mu (with cervical [C], middle [M], and incisal [I] region) 5Y-PSZ and randomly sintered at decreasing (Td: 1,450°C), regular (Tr: 1,500°C), and increasing (TI: 1,550°C) sintering temperature, with extremely short (He: 10 minutes), ultrashort (Hu: 15 minutes), short (Hs: 30 minutes), and regular (Hr: 135 minutes) sintering time (n = 15/group). Color appearance (EW ), translucency parameter (TP), contrast ratio (CR), opalescence parameter (OP), and color appearance difference (∆E diff) were evaluated in the CIE L*a*b* system. Microstructures were evaluated by scanning electron microscope (SEM) and X-ray diffractometer (XRD). Statistical Analysis Analysis of variance (ANOVA) and Bonferroni comparisons were determined for significant differences (p < 0.05). Results Significant differences in color parameters upon zirconia type, sintering temperature, and sintering time, and their interactions were indicated (p < 0.05). Increasing sintering temperature and extended sintered time resulted in larger grain, reduced tetragonal-to-monoclinic phase transformation, and significantly increased the TP and OP, but decreased the CR and ∆E diff (p < 0.05). Decreasing sintering temperature and time led to clinically unacceptable color appearance. Conclusion Mo was found to be more translucent than Mu. To achieve the most favorable optical properties, increasing sintering temperature and extending sintering time are recommended. Decreasing sintering temperature is not suggested. However, shortened sintering time is feasible, but it needs sintering with increasing sintering temperature to achieve a promising color appearance.

Improvement of gram staining effect by ethanol pretreatment and quantization of staining image by unsupervised machine learning.

In this study, we propose an Ethanol Pretreatment Gram staining method that significantly enhances the color contrast of the stain, thereby improving the accuracy of judgement, and demonstrated the effectiveness of the modification by eliminating unaided-eye observational errors with unsupervised machine learning image analysis. By comparing the traditional Gram staining method with the improved method on various bacterial samples, results showed that the improved method offers distinct color contrast. Using multimodal assessment strategies, including unaided-eye observation, manual image segmentation, and advanced unsupervised machine learning automatic image segmentation, the practicality of ethanol pretreatment on Gram staining was comprehensively validated. In our quantitative analysis, the application of the CIEDE2000, and CMC color difference standards confirmed the significant effect of the method in enhancing the discrimination of Gram staining.This study not only improved the efficacy of Gram staining, but also provided a more accurate and standardized strategy for analyzing Gram staining results, which might provide an useful analytical tool in microbiological diagnostics.

Low luminance contrast’s effect on the color appearance of S-cone patterns

There is a surprisingly strong effect on color appearance when low levels of luminance contrast are added to visual targets in which only S-cones are modulated. This phenomenon can be studied with checkerboard patterns composed of alternating S-cone-modulated checks and gray checks. + S checks look purple when surrounded by slightly brighter gray checks but look highly desaturated (lavender, almost white) when surrounded by darker gray checks. −S checks change in hue with luminance contrast; they look yellow when surrounded by darker gray checks but are greener when surrounded by lighter checks. Psychophysical paired comparisons confirm these perceptions. Furthermore, visual evoked potentials (VEPs) recorded from human posterior cortex indicate that signals evoked by low luminance contrast interact nonlinearly with S-cone-evoked signals in early cortical color processing. Our new psychophysics and electrophysiology results prove that human perception of color appearance is not based on neural computations within a separate, isolated color system. Rather, signals evoked by color contrast and luminance contrast interact to produce the colors we see.

Underwater image enhancement via color correction and multi-feature image fusion

Abstract The light attenuation underwater causes the actual underwater images to suffer from color cast, low contrast, and weak illumination. To address these issues, an effective fusion-based method is proposed, which realizes color correction, brightness adjustment, contrast, and detail enhancement of underwater images. Concretely, we first design an adaptive color correction method via dominant color channel judgment and lower color channel compensation. Then, we detect the brightness of each input image and propose a gamma correction function based on the gradient of the cumulative histogram to adjust the brightness of the low-light images. Subsequently, global histogram stretching and adaptive fractional differentiation techniques are employed to process the brightness-adjusted image, and then the global contrast-enhanced version and detail-enhanced version are generated respectively. To integrate the advantages of both versions, a channel fusion method based on the Lab color space is used to fuse the luminance and color of the two versions separately. The experimental results demonstrate the effectiveness of the proposed method in improving the color and illumination of underwater images, as well as enhancing the clarity of images. Moreover, the testing results on multiple datasets validate the excellent stability of this method.

MCRNet: Underwater image enhancement using multi-color space residual network

The selective attenuation and scattering of light in underwater environments cause color distortion and contrast reduction in underwater images, which can impede the ever-growing demand for underwater robot operations. To address these issues, we propose a Multi-Color space Residual Network (MCRNet) for underwater image enhancement. Our method takes advantage of the unique features of color representation in the RGB, HSV, and Lab color spaces. By utilizing the distinct feature representations of images in different color spaces, we can highlight and fuse the most informative features of the three color spaces. Our approach employs a self-attention mechanism in the multi-color space feature fusion module. Extensive experiments demonstrate that our method achieves satisfactory results in color correction and contrast improvement of underwater images, particularly in severely degraded scenes. Consequently, our method outperforms state-of-the-art methods in both subjective visual comparison and objective evaluation metrics.

Tuning up of chromism, luminescence in cadmium-viologen complexes through polymorphism strategy: Inkless erasable printing application

In our work, polymorphism strategy has been successfully applied to tune up chromism and luminescence properties of viologen-based materials. Two polymorphs of viologen-based complexes of α-CdBr2(PHSQ)2(H2O)2 (1) and β-CdBr2(PHSQ)2(H2O)2 (2) (PHSQ = N-(4-sulfophenyl)-4,4′-bipyridinium) were synthesized by changing the solvent. They can both respond to UV light and electricity in the manner of chromism visible to the naked eye and the coloration states have good reversibility, through which an inkless erasable printing model has been established. But the coloration contrast of 1 is higher compared to 2. Meanwhile, they both exhibit photoluminescence properties and the intensity of 1 is twice that of 2, which is accompanied by photoquenching upon continuous UV light irradiation. The only divergence of disordered/ordered O atoms in the two crystalline compounds leads to significantly different chromic and luminescent properties. Further explorations simultaneously demonstrate that the different chromic performance between 1 and 2 should attribute to the alteration of stimulus-induced (light/ electricity) electron transfer channels caused by the ordered/disordered O atoms in the complexes, which is achieved through CH···O and OH···O interactions to change crystal arrangement and structural rigidity, thus affect luminescent properties.

Effect of Amblyopia on Color Vision and Contrast Sensitivity: A Systematic Review

Effect of Amblyopia on Color Vision and Contrast Sensitivity: A Systematic Review

Youth attention, perceptions, and appeal in response to e-cigarette advertising features: A focus group study

BackgroundE-cigarette marketing exposure may influence vaping-related outcomes among youth, but less is known on which specific advertising features impact youth attention, perceptions, and appeal. This study qualitatively examines responses to different e-cigarette advertising features among e-cigarette-naïve youth. MethodsWe conducted four online focus groups in 2021 with a national U.S. sample of 13–17 year olds (n = 25) who had never used e-cigarettes. Participants viewed and discussed their reactions to different e-cigarette advertisements varying in the inclusion of ad features, including color, models in imagery, text claims targeting smokers, and the nicotine warning label. ResultsParticipants were attracted to ads with bright colors, particularly when contrasted against a dark background. Ads featuring models attracted attention and reduced perceptions that the product is harmful. Comments indicated mixed reactions to smoker-targeted text claims. On one hand, participants perceived ads with text that specified “for smokers” as targeting older adults. On the other hand, text referring to “switching” from cigarettes to e-cigarettes led to some perceptions that the product is healthy, and certain text that implicitly referred to smoking (e.g., “no odor”) had the potential to appeal to youth who wanted to use e-cigarettes discreetly. The level of attention paid to warnings depended on warning size and the color contrast between the warning and the rest of the ad. ConclusionsFindings suggest specific e-cigarette ad features play an important role in attracting youth attention and influencing perceptions. More research is needed on the potential public health benefits versus unintended consequences of smoker-targeted text claims.

Buffered Oxide Etch: A Safer, More Effective Etchant for Additively Manufactured Ti-Alloys

Kroll’s reagent is effective for the metallographic etching of traditional Ti-alloys but struggles with the intricate, refined microstructures of newer Ti-alloy compositions like Ti-Cu and Ti-Mo alloys, which are created through additive manufacturing. The presence of fine intermetallic compounds in these alloys results in limited contrast between grains and phases when using Kroll’s reagent, highlighting the need for an alternative etchant. This study systematically investigates the use of buffered oxide etch, a common etchant for micro-electronics, on a range of additively manufactured Ti-alloys. The results show that buffered oxide etch provides superior etching outcomes compared to Kroll’s reagent and ammonium bifluoride, with a clear colour contrast between grains and fine phases. Furthermore, ammonium bifluoride with an F− ion concentration similar to 40% buffered oxide etch (5.60 mmol/ml) is found to reveal microstructural details effectively. These findings suggest that the buffered oxide etch is a reliable tint etchant for additively manufactured Ti-alloys, and could potentially be used to etch other additively manufactured alloy systems for metallographic studies. Both these etchants supply F− ions without the low pH, significantly improving safety by removing the need for HF in the etching process.

Homogenization of the Color of Beech Sapwood and False Heartwood by the Steaming Process

This work presents the results of the homogenization of the color of sapwood and false heartwood Fagus sylvatica L. into a uniform color shade due to the influence of the temperature of saturated moist air and saturated water steam in individual steaming modes. The results of analyses of the influence of temperature within 24 h point out the different changes in the color of the sapwood and the wood of the false heartwood when the uniform color of the beech wood is achieved by the steaming process. By steaming beech wood with a false heartwood saturated with moist air at a temperature of tI = 95 °C during τ = 24 h, the color of the sapwood does not merge with the color of the wood of the false heartwood. The sapwood darkens and, on the other hand, the wood of the false heartwood slightly lightens, while the significant color contrast is removed, but the color homogenization in the individual zones does not occur. The unification of the colors in individual zones occurs during the steaming process at a temperature of saturated water steam tII ≈ 105 °C in 18 h, where the resulting brown color is identified in the color space CIE L*a*b* by the values of the lightness L* = 61.3 ± 2.2 and of the red color a* = 12.4 ± 1.3 and yellow color b* = 19.5 ± 1.4. The most pronounced homogenization of the color occurs through the steaming process at a temperature of saturated water steam tIII ≈ 120 °C, where the wood acquires a uniform dark brown–gray color in a time of τ ≈ 9 h steaming. The coordinates of the color-homogenized steamed beech wood are L* = 55.9 ± 1.9, a* = 12.3 ± 1.2, and b* = 19.6 ± 1.3. The unification of the colors by the steaming process is achieved by darkening both the sapwood and the wood of the false heartwood. In the overall color homogenization, the sapwood and the wood of the false heartwood do not participate equally in the steaming process. While the total color difference between the sapwood and a color homogenized state is quantified by the value ∆EtI* = 8, ∆EtIII* = 22.7, the total color difference in the wood with a false heartwood is only ∆EtI* = 1.9, ∆EtIII* = 11.8.

Enhancing Accessibility through Typography in Thai Government Mobile Applications: Identifying Issues and Recommending Inclusive Guidelines for Typefaces, Type Sizes, and Color Contrast

Enhancing Accessibility through Typography in Thai Government Mobile Applications: Identifying Issues and Recommending Inclusive Guidelines for Typefaces, Type Sizes, and Color Contrast

Diagnostic value of contrast-enhanced ultrasonography for patent foramen ovale detection.

Patent foramen ovale (PFO) has been associated with migraine, cryptogenic stroke (CS), and hypoxemia. However, which examination method is most reliable remains controversial. This study sought to investigate the diagnostic value of contrast-enhanced ultrasonography (cU), including contrast-enhanced transcranial Doppler (cTCD), contrast transthoracic echocardiography (cTTE), and contrast transesophageal echocardiography (cTEE), for PFO; and to determine the best diagnostic strategy. This retrospective observational study included a total of 147 consecutive patients suspected PFO at The First Hospital of Shanxi Medical University between October 2019 and January 2022. The patients also underwent cTCD, cTTE, and cTEE examinations. The standard for the diagnosis of PFO was confirmation of the presence of PFO by color Doppler flow signals or contrast microbubbles (MBs) passing through the foramen ovale. A total of 123 patients were diagnosed with PFO and 24 patients without PFO during the study period. The detectable rates of cTCD, cTTE, and cTEE were 120 (97.56%), 110 (89.43%), and 121 (98.37%), respectively. The sensitivity between cTCD and cTEE for PFO were comparable [97.56%, 95% confidence interval (CI): 92.5% to 99.4% vs. 98.37%, 95% CI: 93.7% to 99.7%; P>0.99], and the sensitivity of both were higher than that of cTTE (89.43%, 95% CI: 82.3% to 94.0%; P=0.02 and P=0.001, respectively). In addition, the specificity of cTEE for PFO was significantly higher than that of cTCD (100%, 95% CI: 82.3% to 100.0% vs. 75.00%, 95% CI: 53.0% to 89.4%; P<0.001) and cTTE (100%, 95% CI: 82.3% to 100.0% vs. 75.00%, 95% CI: 53.0% to 89.4%; P<0.001). Further, the semi-quantitative classification ability of cTCD for PFO with right-to-left shunt (RLS) was significantly higher than that of cTTE and cTEE (P=0.02 and P<0.001, respectively), and that of cTTE was significantly higher than that of cTEE (P=0.01). The Spearman analysis showed that the degree of RLS was positively correlated with the inner diameter of the PFO (r=0.695, P<0.001). The combination of cTCD and cTEE may provide a favorable strategy for the diagnosis of PFO.

Effect of changes in surface visual properties of heat-treated wood on the psychological preference

Heat treatment of wood is an attractive, environmentally friendly modification, which can change surface visual properties of wood including color and grain, but it is unclear how heat-treated wood is perceived and evaluated compared with untreated wood. In this paper, Chinese fir was heat-treated at 160, 180, 200, or 220 °C for 2 or 4 h. The changes of wood surface color and grain contrast were measured. A subjective questionnaire and eye-tracking technology were used for psychological evaluation. The results showed that changes in the visual properties of heat-treated wood had a significant effect on psychological preference—heat-treated wood was generally more preferred than the untreated, particularly at 200 °C for 4 h. Grain contrast and hue played an important role in the preference for heat-treated wood. The preference gave people the positive psychological impression of warmth, weight, cost, prevalence, and comfort. Eye-tracking analysis showed that Chinese fir heat-treated at about 200 °C with high hue value and clear grain contrast was easier to gain more visual attention. The results would have a high technical reference value for the heat-treated wood in product visual design.

AI-Enhanced Accessibility Solutions using Chatbot

The "AI-Enhanced Accessibility Solutions" project addresses the real-world challenge of enhancing accessibility for individuals through advanced technologies. Utilizing React.js, Next.js, Tailwind, and AI APIs, this study focuses on generating inclusive content, including text, images, videos, code, and chatbot interactions. The primary objectives are to improve user interfaces, employ AI-driven content generation techniques, and ensure compliance with accessibility standards. The platform allows users to input self-generated prompts to produce customized data, such as text, images, videos, and code, tailored to their needs. An interactive AI-powered chatbot assists users in daily activities, adapting responses based on the quality of prompts provided, ensuring personalized and effective results. Key features include AI-generated content designed for various abilities. This includes alternative text for images, simplified text for cognitive accessibility, and adaptive chatbot responses. The project also focuses on generating accessible code, adhering to best web development practices. Tailwind CSS is used to optimize content presentation, addressing factors like color contrast and readability. The study includes a comparative analysis of accessibility features in popular apps versus those generated by our system. User testing and feedback mechanisms are employed to validate the project's effectiveness in meeting diverse user needs. This project not only advances AI-driven content creation but also represents a significant step towards creating inclusive digital environments. It emphasizes the importance of accessibility in technology, ensuring that digital content is accessible to all individuals, regardless of their abilities. Keywords: AI-Enhanced Accessibility, Inclusive Content, React.js, Next.js, AI APIs, User Interfaces, Accessibility Standards, AI-Powered Chatbot, Cognitive Accessibility

Enhancing the Usability, Visibility, and Responsiveness of an Airline Reservation System: A User-Centered Design Approach

This paper presents the idea, design, and prototype of a flight search and airline booking system based on the perspective of user-centered design. The system is first sketched roughly on paper in the form of a sketched plan and implemented through the proper system by connecting with the rapid API to develop a responsive web application. Booking travel tickets is a hassle and quite stressful because there is a chance that the webpages take time, and several decisions to make, hard to choose a discounted or less expensive flight, and the user will have to put in a lot of effort with many browser tabs may leave open. If a user is looking for the lowest travel options within a range of dates, they need to search a lot of websites looking for better options. As UX designers, it is our responsibility to do some user research and identify the problem areas, then we will recommend some design options based on the research findings. After that, we will create a wireframe and prototype before jumping into web design by collecting all the requirements and analyzing the problems. We will be focusing on UI controls such as location picker, date picker, color contrast, accessibility, and so on. In this paper, we present the design and development of a user-centered flight search and booking system for the airline industry. Our goal is to create a system that would meet the needs and preferences of a diverse set of users. This paper will summarize the design, development, and implementation of an airline reservation system. We have used bubble.io to design the overall system and MYSQL as the database management system for this webpage. Our objective is to upgrade the current website by improving the usability, visibility, and responsiveness of the functions that the user will experience while buying a flight ticket. We have generated and managed the design documentation and a perfect user-based online flight booking system.

Utilizing rare earth titanates to improve performance of solid-state electrochromic device

Exploring new materials and synthesis recipes are required to enhance the electrochromic performance especially, when used in solid-state devices. Here, polycrystalline gadolinium titanate (Gd2TiO5 or GTO), synthesized using a simple solid-state reaction method, has been used for this purpose by combining it with polythiophene (P3HT). The electrochemical investigation of the Gd2TiO5 doped P3HT electrode has been carried out using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), which reveals the dominance of diffusion-controlled mechanism over charge storage on the electrode surface as compared to the P3HT electrode. The Gd2TiO5 doped P3HT solid-state electrochromic device shows color modulation at 515 nm and 670 nm wavelengths with a color contrast of as high as 79% and 42%, respectively, under an external bias of as low as ±1.4 V. The prepared device switches between maroon to a transparent state in less than a second under the external bias (±1.4 V) with a high coloration efficiency of 346 cm2/C. The device shows improved cycle life over 100 switching cycles at both the wavelengths, which makes it more suitable for real-life applications.

Color Contrast: Racial and Ethnic Disparities in New York City Law Enforcement

Color Contrast: Racial and Ethnic Disparities in New York City Law Enforcement

Integrating Electrochemically Grown Nano‐Oxide and Polymer Films for Electrochromic Device: Achieving Near‐Infrared Shielding and Four‐Digit Efficiency

Electrochemically deposited thin films yield high uniformity, a property which is quite vital to in the context of electrochromic (EC) coatings and devices. Tungsten oxide and polyaniline are two such materials that show superior EC properties individually. However, when combined into a solid‐state device structure, they yield a device where the efficiency increases multifolds. This device combination, being thoroughly characterized in the domain of EC parameters such as high switching speeds, rich color contrast, and stability, is found to be an excellent complementary EC pair. The unique property of the said device is that it can reduce the transmission of wavelengths in the near‐infrared region of the electromagnetic spectrum, providing an edge over other such combinations. In addition, a four‐digit value of coloration efficiency makes this device stand out in the family of its contemporaries. Overall, the hybrid nature of the device prompts it to be an excellent combination indicating its high performance in terms of increased endurance and heat isolation capacity.

Intrinsic-style distribution matching for arbitrary style transfer

Although arbitrary style transfer has been a hot topic in computer vision, most existing methods that directly align style and content features frequently result in unnatural effects in the generated images, such as over-stylization and style leakage. In this paper, we introduce a novel progressive Intrinsic-style Distribution Matching (ISDM) approach which initially aligns the intrinsic style distribution of both style and content images and then integrates it with the image’s content component. This novel approach can effectively alleviate the issue of over-stylization while preserving the content structure, particularly in the case of high contrast and vivid colors. To further enhance the performance of our method, we propose a learnable multi-level style modulation module to assist the network in aligning the intrinsic style distributions. Moreover, two contrastive objectives are proposed to improve the ability of the encoder to extract more distinct and representative intrinsic content and intrinsic style features. Extensive experimental results showcase that our approach can preserve more content details than state-of-the-art methods. It can also generate more natural images, especially when the style image has high contrast and vivid colors.