Color Confusion Research Articles

Psudo: Exploring Multi-Channel Biomedical Image Data with Spatially and Perceptually Optimized Pseudocoloring.

Over the past century, multichannel fluorescence imaging has been pivotal in myriad scientific breakthroughs by enabling the spatial visualization of proteins within a biological sample. With the shift to digital methods and visualization software, experts can now flexibly pseudocolor and combine image channels, each corresponding to a different protein, to explore their spatial relationships. We thus propose psudo, an interactive system that allows users to create optimal color palettes for multichannel spatial data. In psudo, a novel optimization method generates palettes that maximize the perceptual differences between channels while mitigating confusing color blending in overlapping channels. We integrate this method into a system that allows users to explore multi-channel image data and compare and evaluate color palettes for their data. An interactive lensing approach provides on-demand feedback on channel overlap and a color confusion metric while giving context to the underlying channel values. Color palettes can be applied globally or, using the lens, to local regions of interest. We evaluate our palette optimization approach using three graphical perception tasks in a crowdsourced user study with 150 participants, showing that users are more accurate at discerning and comparing the underlying data using our approach. Additionally, we showcase psudo in a case study exploring the complex immune responses in cancer tissue data with a biologist.

Analyzing the effect of blue-blocking lenses on color vision tests using the chromaticity coordinate method

SignificanceBlue light with wavelengths of 380–445 nm can harm the retina, leading to the development of blue-blocking lenses (BBLs). Understanding whether BBLs affect color vision test outcomes and color discrimination ability is crucial for people in color-associated jobs. AimThis study aimed to evaluate the effect of BBLs on color vision tests and analyze color discrimination using mathematical models of color spaces. ApproachSix pseudoisochromatic (PIC) tests and two Farnsworth-Munsell (FM) tests were conducted to assess participants’ color vision. Friedman signed rank test was used to compare the outcomes of the Farnsworth-Munsell 100-Hue Tests (FM 100-Hue Tests) between the BBLs and ordinary lenses groups. The CIE color difference formula and a spectral illuminometer were employed to evaluate the color differences with and without BBLs. ResultsAll subjects showed normal outcomes in all PIC tests and Farnsworth-Munsell Dichotomous D-15 Tests (FM D-15 Tests). There were no significant differences between ordinary lenses group and BBLs groups in FM 100-Hue Tests. In the color space, the effect of BBLs on each color light was equivalent to a translation on the CIE 1931 chromaticity diagram with minor distortion. Since BBLs do not disrupt the continuity of the chromaticity diagram, or cause different colors to appear the same, they do not lead to color confusion. However, colors with short wavelengths exhibited more changes in color difference when wearing BBLs. ConclusionsBBLs do not impair the wearer's ability to discriminate colors or perform color vision tests accurately. However, BBLs can cause color differences especially in the recognition of blue hues.

Chromatic discrimination in fixed saturation levels from tufted capuchin monkeys with different color vision genotypes.

Recent research has proposed new approaches to investigate color vision in Old World Monkeys by measuring suprathreshold chromatic discrimination. In this study, we aimed to extend this approach to New World Monkeys with different color vision genotypes by examining their performance in chromatic discrimination tasks along different fixed chromatic saturation axes. Four tufted capuchin monkeys were included in the study, and their color vision genotypes were one classical protanope, one classical deuteranope, one non-classical protanope, and a normal trichromat. During the experiments, the monkeys were required to perform a chromatic discrimination task using pseudoisochromatic stimuli with varying target saturations of 0.06, 0.04, 0.03, and 0.02 u'v' units. The number of errors made by the monkeys along different chromatic axes was recorded, and their performance was quantified using the binomial probability of their hits during the tests. Our results showed that dichromatic monkeys made more errors near the color confusion lines associated with their specific color vision genotypes, while the trichromatic monkey did not demonstrate any systematic errors. At high chromatic saturation, the trichromatic monkey had significant hits in the chromatic axes around the 180° chromatic axis, whereas the dichromatic monkeys had errors in colors around the color confusion lines. At lower saturation, the performance of the dichromatic monkeys became more challenging to differentiate among the three types, but it was still distinct from that of the trichromatic monkey. In conclusion, our findings suggest that high saturation conditions can be used to identify the color vision dichromatic phenotype of capuchin monkeys, while low chromatic saturation conditions enable the distinction between trichromats and dichromats. These results extend the understanding of color vision in New World Monkeys and highlight the usefulness of suprathreshold chromatic discrimination measures in exploring color vision in non-human primates.

Reduced eye optical quality contributes to worse chromatic thresholds in aging.

Aging causes substantial changes in the intraocular lens, which leads to a reduction in chromatic perception. We aimed to measure the ocular light dispersion component in relation to the reduction in color vision by aging. Intraocular straylight was quantified psychophysically by C-Quant for light dispersion [Log(s)], reliability of the results (ESD), and psychometric sampling quality (Q). The Cambridge Color Test Trivector protocol measured the chromaticity thresholds for protan, deutan, and tritan color confusion axis in CIE 1976 u' v' units. We tested 224 subjects aged 24-68 years (106 men) with normal best-corrected visual acuity and without clinical evidence of cataracts. A significant positive correlation was found between ocular dispersion of light and chromaticity thresholds for protan (r = 0.42; p < 0.001), deutan (r = 0.49; p < 0.001) and tritan (r = 0.51; p < 0.0001) color confusion axes with a moderate effect size (η2 = 0.39). However, a weak contribution of the logarithm of the straylight in predicting the chromaticity threshold for protan (b = 0.15; p = 0.025), deutan (b = 0.27; p = 0.001) and tritan (b = 0.21; p = 0.001) color confusion axes was verified in the regression coefficients. The other two measurement quality parameters estimated in the C-Quant were not correlated with chromaticity thresholds, suggesting that there are no problems with the quality of the measurement performed. An increase in ocular light dispersion that occurs physiologically with aging negatively impacts the chromaticity threshold in a similar manner across all three color confusion axes. The weak regression effects suggest that neural rather than optical processes were more related to the reduction in chromaticity in aging.

Visual Characteristics of Adults with Long-Standing History of Dietary Exposure to Mercury in Grassy Narrows First Nation, Canada.

Since the 1960s, Grassy Narrows First Nation (Ontario, Canada) has been exposed to methyl mercury (Hg) through fish consumption, resulting from industrial pollution of their territorial waters. This cross-sectional study describes the visual characteristics of adults with documented Hg exposure between 1970 and 1997. Oculo-visual examinations of 80 community members included visual acuity, automated visual fields, optical coherence tomography [OCT], color vision and contrast sensitivity. Median age was 57 years (IQR 51-63) and 55% of participants were women. Median visual acuity was 0.1 logMAR (Snellen 6/6.4; IQR 0-0.2). A total of 26% of participants presented a Visual Field Index inferior to 62%, and qualitative losses assessment showed concentric constriction (18%), end-stage concentric loss (18%), and complex defects (24%). On OCT, retinal nerve fiber layer scans showed 74% of participants within normal/green range. For color testing with the Hardy, Rand, and Rittler test, 40% presented at least one type of color defect, and with the Lanthony D-15 test, median color confusion index was 1.59 (IQR 1.33-1.96). Contrast sensitivity showed moderate loss for 83% of participants. These findings demonstrate important loss of visual field, color vision, and contrast sensitivity in older adults in a context of long-term exposure to Hg in Grassy Narrows First Nation.

Low-level occupational exposure to BTEX and dyschromatopsia: a systematic review and meta-analysis

Objectives. The present study aimed to assess whether occupational exposure to low concentrations of benzene, toluene, ethylbenzene and xylene (BTEX) is associated with color vision impairment. Methods. We queried PubMed, Scopus, Embase, Web of Science and ProQuest as the main databases, as well as gray literature such as Google Scholar. A random-effects model was used to assess relative risk. A funnel plot was created to assess publication bias. Meta-regression analysis was applied to identify variables that explain the between-study variation in the reported risk estimate. Results. An overall standardized mean difference of 0.529 (95% confidence interval [0.269, 0.788]; p < 0.0001) was obtained in the random-effects model, which corresponded to a medium-size effect. Duration and the levels of exposure to benzene, toluene and xylene were the significant predictors of the magnitude of the combined risk estimate. Chronic exposure to low levels of BTEX was associated with dyschromatopsia determined by the color confusion index. Conclusions. The impairments can occur even at exposures lower than the occupational exposure limits of BTEX. However, there are several flaws in the determination of workers’ exposure, which did not allow to establish how low a level of these chemicals can cause color vision impairment.

An Unpaired Thermal Infrared Image Translation Method Using GMA-CycleGAN

Automatically translating chromaticity-free thermal infrared (TIR) images into realistic color visible (CV) images is of great significance for autonomous vehicles, emergency rescue, robot navigation, nighttime video surveillance, and many other fields. Most recent designs use end-to-end neural networks to translate TIR directly to CV; however, compared to these networks, TIR has low contrast and an unclear texture for CV translation. Thus, directly translating the TIR temperature value of only one channel to the RGB color value of three channels without adding additional constraints or semantic information does not handle the one-to-three mapping problem between different domains in a good way, causing the translated CV images not only to have blurred edges but also color confusion. As for the methodology of the work, considering that in the translation from TIR to CV the most important process is to map information from the temperature domain into the color domain, an improved CycleGAN (GMA-CycleGAN) is proposed in this work in order to translate TIR images to grayscale visible (GV) images. Although the two domains have different properties, the numerical mapping is one-to-one, which reduces the color confusion caused by one-to-three mapping when translating TIR to CV. Then, a GV-CV translation network is applied to obtain CV images. Since the process of decomposing GV images into CV images is carried out in the same domain, edge blurring can be avoided. To enhance the boundary gradient between the object (pedestrian and vehicle) and the background, a mask attention module based on the TIR temperature mask and the CV semantic mask is designed without increasing the network parameters, and it is added to the feature encoding and decoding convolution layers of the CycleGAN generator. Moreover, a perceptual loss term is applied to the original CycleGAN loss function to bring the translated images closer to the real images regarding the space feature. In order to verify the effectiveness of the proposed method, the FLIR dataset is used for experiments, and the obtained results show that, compared to the state-of-the-art model, the subjective quality of the translated CV images obtained by the proposed method is better, as the objective evaluation metric FID (Fréchet inception distance) is reduced by 2.42 and the PSNR (peak signal-to-noise ratio) is improved by 1.43.

Elaborate Evaluation of Farnsworth Dichotomous D-15 Panel Test Can Help Differentiate between Best Vitelliform Macular Dystrophy and Autosomal Recessive Bestrophinopathy

Introduction: The colour vision in bestrophinopathies has not been assessed in detail so far. The aim of this study was to explore the extent to which distinct types of bestrophinopathies differ in regard to colour vision deficiencies using Farnsworth Dichotomous D-15 and Lanthony Desaturated D-15 panel tests. Methods: Both D-15 tests were performed in 52 eyes of 26 patients with Best vitelliform macular dystrophy (BVMD) and 10 eyes of 5 patients with autosomal recessive bestrophinopathy (ARB). Two methods were used for a quantitative assessment of the colour vision deficiencies: moment of inertia method and Bowman method. The following parameters were calculated: confusion angle, confusion index (C-index), selectivity index (S-index), total error score (TES), and colour confusion index (CCI). Results: The median value of confusion angle for all stages of BVMD fell into a narrow range around 62, indicating normal results. The median confusion angle value was 57 in ARB patients within a very wide range down to −82, indicating non-specific deficits. These differences were statistically significant. Significantly abnormal C-index and CCI values were found only in ARB patients, being 2.0 and 1.49, respectively. The majority of parameters of D-15 tests were independent of the visual acuity in both bestrophinopathies. Conclusions: Elaborate evaluation of the D-15 panel tests might help establish a differential diagnosis between different bestrophinopathies, as the pattern of the colour vision loss is different between BVMD and ARB. The quantitative parameters of colour vision tests in bestrophinopathies are independent of the visual acuity.

Dyschromatopsia in multiple sclerosis reflects diffuse chronic neurodegeneration beyond anatomical landmarks

AbstractPurpose: To formulate and validate a dyschromatopsia linear regression model in patients with multiple sclerosis (MS).Methods: 64 MS patients (50 to formulate the model and 14 for its validation) underwent neurological (Expanded Disability Status Scale, EDSS), colour vision (Farnsworth D15 test), and peripapillary retinal nerve fibre layer (pRNFL) and retinal evaluation with spectral‐domain optical coherence tomography (SD‐OCT). Neuroradiological examination permitted to obtain brain parenchymal fraction (BPF) and cervical spinal cord volume (SC). Ophthalmic parameters were calculated as the average of both non‐optic neuritis (ON) eyes, and in case the patient had previous ON, the value of the fellow non‐ON eye was taken. The influence of sex, age, disease duration and history of disease‐modifying treatment (first‐ or second‐line DMT) was tested as covariables that could influence colour perception.Results: Colour confusion index (log CCI) correlated with pRNFL (r = −0.322, p = 0.009), ganglion cell layer (GCL, r = −0.321, p = 0.01), BPF (r = −0.287, p = 0.021), SC volume (r = −0.33, p = 0.008), patients' age (r = 0.417, p = 0.001), disease duration (r = 0.371, p = 0.003) and EDSS (r = 0.44, p = 0.001). The following CCI equation was obtained: log (CCI) = 0.316–0.224 BPF –0.187 SC volume (mm3) +0.226 age (years) +0.012 disease duration (years) −0.372 GCL (μm).Conclusions: CCI correlates with MS clinical and paraclinical established biomarkers suggesting chronic diffuse neurodegeneration in MS operates at brain, SC and retina linking all three compartments. Colour vision outcome can be calculated through the aforementioned variables for clinical and research purposes.

The Association Between Acquired Color Deficiency and PET Imaging of Neurodegeneration in Mild Cognitive Impairment and Alzheimer Disease.

PurposeTo evaluate color vision changes and retinal processing of chromatic and luminance pathways in subjects with Alzheimer disease (AD) and mild cognitive impairment (MCI) compared with a matched control group and whether such changes are associated with impaired brain glucose metabolism and β-amyloid deposition in the brain.MethodsWe evaluated 13 patients with AD (72.4 ± 7.7 years), 23 patients with MCI (72.5 ± 5.5 years), and 18 controls of comparable age (P = 0.44) using Cambridge color test and the heterochromatic flicker ERG (HF-ERG). The Cambridge color test was performed using the trivector protocol to estimate the protan, deutan and tritan color confusion axes. HF-ERG responses were measured at a frequency of 12 Hz, which ERGs reflect chromatic activity, and at 36 Hz, reflecting luminance pathway. A study subsample was performed using neuropsychological assessments and positron emission tomography.ResultsPatients with AD presented higher mean values indicating poorer color discrimination for protan (P = 0.04) and deutan (P = 0.001) axes compared with the controls. Along the tritan axis, both patients with AD and patients with MCI showed decreased color vision (P = 0.001 and P = 0.001) compared with controls. The analyses from the HF-ERG protocol revealed no differences between the groups (P = 0.31 and P = 0.41). Diffuse color vision loss was found in individuals with signs of neurodegeneration (protan P = 0.002, deutan P = 0.003 and tritan P = 0.01), but not in individuals with signs of β-amyloid deposition only (protan P = 0.39, deutan P = 0.48, tritan P = 0.63), regardless of their clinical classification.ConclusionsHere, patients with AD and patients with MCI present acquired color vision deficiency that may be linked with impaired brain metabolism.

Color Vision in the Gas Station Workers of Isfahan City: A Quantitative Analysis With the Farnsworth D15 Color Test

Background and Objectives: The color vision evaluation of gas station workers in Isfahan City. Methods: This cross-sectional comparative study was performed on workers at gas stations in Isfahan; all the workers were men. The participants were divided into two 40-people groups of exposure and non-exposure (the members of the fuel sales department). The participants had better vision than 8/10 and no underlying problems or eye disease. Besides, examination, including color vision was performed for all subjects. Color vision was assessed using the D15 test under high to medium light conditions. Also, the color vision test was performed monocularly. Then, the obtained data were analyzed using SPSS V. 22. Results: The two study groups significantly differed in terms of color vision impairment index (P &lt;0.001). Also, more color vision defects were seen in the group exposed to gasoline. The color confusion index (as the indicator of color vision defects) were 1.485 and 1.129 in exposure and non-exposure to gasoline groups, respectively. Thus, color vision defects were significantly higher in the exposure to gasoline group, compared with the control group. Conclusion: The results of this study showed a difference in color vision index between the two groups. Therefore, long-term exposure to organic solvents, such as gasoline in fuel stations may cause color vision loss.

An end-to-end framework for unconstrained monocular 3D hand pose estimation

This work addresses the challenging problem of unconstrained 3D hand pose estimation using monocular RGB images. Most of the existing approaches assume some prior knowledge of hand (such as hand locations and side information) is available for 3D hand pose estimation. This restricts their use in unconstrained environments. Therefore, we present an end-to-end framework that robustly predicts hand prior information and accurately infers 3D hand pose by learning ConvNet models while only using keypoint annotations. To enhance the hand detector’s robustness, we propose a novel keypoint-based method to simultaneously predict hand regions and side labels, unlike existing methods that suffer from background color confusion caused by using segmentation or detection-based technology. Moreover, inspired by the human hand’s biological structure, we introduce two geometric constraints directly into the 3D coordinates prediction that further improves its performance. Experimental results show that our proposed framework outperforms the state-of-art methods on standard benchmark datasets while providing robust predictions.

Specificity of the chromatic noise influence on the luminance contrast discrimination to the color vision phenotype

Many studies have examined how color and luminance information are processed in the visual system. It has been observed that chromatic noise masked luminance discrimination in trichromats and that luminance thresholds increased as a function of noise saturation. Here, we aimed to compare chromatic noise inhibition on the luminance thresholds of trichromats and subjects with severe deutan or protan losses. Twenty-two age-matched subjects were evaluated, 12 trichromats and 10 with congenital color vision impairment: 5 protanopes/protanomalous, and 5 deuteranopes/deuteranomalous. We used a mosaic of circles containing chromatic noise consisting of 8 chromaticities around protan, deutan, and tritan confusion lines. A subset of the circles differed in the remaining circles by the luminance arising from a C-shaped central target. All the participants were tested in 4 chromatic noise saturation conditions (0.04, 0.02, 0.01, 0.005 u′v′ units) and 1 condition without chromatic noise. We observed that trichromats had an increasing luminance threshold as a function of chromatic noise saturation under all chromatic noise conditions. The subjects with color vision deficiencies displayed no changes in the luminance threshold across the different chromatic noise saturations when the noise was composed of chromaticities close to their color confusion lines (protan and deutan chromatic noise). However, for tritan chromatic noise, they were found to have similar results to the trichromats. The use of chromatic noise masking on luminance threshold estimates could help to simultaneously examine the processing of luminance and color information. A comparison between luminance contrast discrimination obtained from no chromatic and high-saturated chromatic noise conditions could be initially undertaken in this double-duty test.

Dyschromatopsia in multiple sclerosis reflects diffuse chronic neurodegeneration beyond anatomical landmarks.

To formulate and validate a dyschromatopsia linear regression model in patients with multiple sclerosis (MS). 64 MS patients (50 to formulate the model and 14 for its validation) underwent neurological (Expanded Disability Status Scale, EDSS), color vision (Farnsworth D15 test), and peripapillary retinal nerve fiber layer (pRNFL) and retinal evaluation with spectral-domain optical coherence tomography (SD-OCT). Neuroradiological examination permitted to obtain brain parenchymal fraction (BPF) and cervical spinal cord volume (SC). Ophthalmic parameters were calculated as the average of both non-optic neuritis (ON) eyes, and in case the patient had previous ON, the value of the fellow non-ON eye was taken. The influence of sex, age, disease duration, and history of disease-modifying treatment (first- or second-line DMT) was tested as covariables that could influence color perception. Color confusion index (log CCI) correlated with pRNFL (r = - 0.322, p = 0.009), ganglion cell layer (GCL, r = - 0.321, p = 0.01), BPF (r = - 0.287, p = 0.021), SC volume (r = - 0.33, p = 0.008), patients' age (r = 0.417, p = 0.001), disease duration (r = 0.371, p = 0.003), and EDSS (r = 0.44, p = 0.001). The following CCI equation was obtained: log (CCI) = 0.316-0.224 BPF -0.187 SC volume (mm3) + 0.226 age (years) + 0.012 disease duration (years) -0.372 GCL (µm). CCI correlates with MS clinical and paraclinical established biomarkers suggesting chronic diffuse neurodegeneration in MS operates at brain, SC, and retina linking all three compartments. Color vision outcome can be calculated through the aforementioned variables for clinical and research purposes.

HUBUNGAN LAMA PAPARAN INHALASI ORGANICSOLVENT TERHADAP PENURUNAN PENGLIHATAN WARNA DAN SENSITIVITAS KONTRAS

&lt;p&gt;&lt;em&gt;Chronic inhalation of organic solvents causes retinal toxicity such as decreased color vision and contrast sensitivity because organic solvents cause damage to photoreceptor function, changes in cortical or retinal neurotransmitter systems such as glutamate, dopamine and acetylcholine and changes in function in parvo, magno and coniocellular cells.&lt;/em&gt;&lt;em&gt; &lt;/em&gt;&lt;strong&gt;&lt;em&gt;Method&lt;/em&gt;&lt;/strong&gt;&lt;em&gt;: The sample of this study consisted of 45 gas station operators who were divided into 3 groups, namely those who worked 1 year&lt;/em&gt;&lt;em&gt;-&lt;/em&gt;&lt;em&gt;5 years, 5 years&lt;/em&gt;&lt;em&gt;-&lt;/em&gt;&lt;em&gt;10 years and &lt;/em&gt;&lt;em&gt;&amp;gt;&lt;/em&gt;&lt;em&gt;10 years. All subjects underwent &lt;/em&gt;&lt;em&gt;q&lt;/em&gt;&lt;em&gt;uantitative color vision examination by calculating the value of the color confusion index (CCI) using Fansworth D15. Contrast sensitivity examination is by determining the log contrast sensitivity value using the Pelli-Robson test.&lt;/em&gt;&lt;em&gt; &lt;/em&gt;&lt;strong&gt;&lt;em&gt;Results&lt;/em&gt;&lt;/strong&gt;&lt;em&gt;: CCI values&amp;gt; 1.00 and log contrast sensitivity values &amp;lt;1.65 were found in officers who worked for &lt;/em&gt;&lt;em&gt;&amp;gt;&lt;/em&gt;&lt;em&gt;10 years by 12 subjects (80%). Statistically there is a significant relationship between the duration of work with the decrease in color vision and contrast sensitivity (P Value 0,000).&lt;/em&gt;&lt;em&gt; &lt;/em&gt;&lt;strong&gt;&lt;em&gt;Conclusion&lt;/em&gt;&lt;/strong&gt;&lt;em&gt;: There is a significant relationship between the duration of exposure to organic solvents with a decrease in color vision and contrast sensitivity in operator officers who work &lt;/em&gt;&lt;em&gt;&amp;gt;&lt;/em&gt;&lt;em&gt;10 years.&lt;/em&gt;&lt;/p&gt;

Evaluation of contrast sensitivity and color vision in lead and zinc mine workers

Purpose. This study was performed to determine achromatic contrast sensitivity and color vision in lead and zinc mine workers. Methods. A total of 230 male workers, who had been working in mine and had been in contact with minerals for at least 1 year, were considered as the case group, and the age of 90 years matched men who have not been in contact with minerals, being regarded as the control group. Contrast sensitivity was assessed using the Freiburg test at three frequencies of 1, 5 and 15 cycles of degree and under low mesopic light condition by two gratings and Landolt C stimuli. Color vision was assessed using the Farnsworth D-15 test under high mesopic light condition. Both tests were carried out monocularly. Data were analyzed using version 22 SPSS software. Results. There was a significant difference between studied groups with Landolt C stimulus in all three frequencies 1, 5 and 15 cycles per degree (p=0.009, p=0.016 and p=0.003). With Grating stimulus, there was a significant difference between the two groups in frequencies of 1 and 15 cycles per degree but at frequency of 5 cycles per degree, there was a border difference (p<0.0001, p=0.051 and p=0.008). A significant difference was observed between color confusion indexes of the two groups (p<0.0001). Conclusion. Chronic exposure to mineral in lead and zinc mine may cause color vision deficiency and decrease in contrast sensitivity. It is recommended that Farnsworth D-15 and Freiburg contrast sensitivity tests would be involved in the early diagnosis of neurodegenerative and visual disorders in workers exposed to minerals.

Image encryption with cross colour field algorithm and improved cascade chaos systems

In this study, the critical factor of the chaos system has been analysed to improve the randomicity of the encryption keyspace. Several chaos systems have been integrated together with a linear function to form a much more efficient key sequence generator. This study also presents the cross colour field confusion method which scrambles the pixels among the R G B colour matrixes. In this way, the range of the pixels scrambling map is extended to three matrixes compared to the traditional pixels scrambling schemes which do pixels scrambling in its own colour matrix. The experiment results show that the improved cascade system has better bifurcation diagrams. The cross colour field diffusion algorithm makes the encrypted image has little pixel correlation and no information leakage. The experiment results justify that the novel cross colour confusion scheme with improved chaos systems has a good ability to resist brute force attack, known plain attack, chosen plain text attack, chosen ciphertext attack and differential attack. The security analysis demonstrates that the proposed approach has satisfactory properties in image encryption.

Evaluation of the Validity of "The Color Confusion Plates for People with Congenital Color Deficiencies"

Evaluation of the Validity of "The Color Confusion Plates for People with Congenital Color Deficiencies"

Assist device in color discrimination using Heilmeier type guest‐host liquid crystal for red‐green color vision defect

AbstractFor assist in color discrimination of color vision defects, the method of observing objects through colored filter has been known. If red filter, which absorbs mostly all light except red light, is used, only the red objects can be highly visible. In this paper, a Heilmeier type guest‐host liquid crystal device with magenta dye was applied to a filter type assist device for red‐green color vision defect. This device can easily control transmittance of green light by changing applied voltage, and make green objects perceived to flicker synchronously. The subjective appraisal of the assist device in color discrimination was performed by five participants with normal vision using a constructed experimental system using a video camera and a PC with a vision simulator. For the confusion indices of the Panel D‐15 test, the effect of the device was statistically significant at P &lt; .01. Moreover, a participant with color vision deficiency assessed it and got results without color confusion on the Panel D‐15 test.

Optimal Color Correction Based on Image Analysis for Color Vision Deficiency

The primary goal of image color correction is to minimize color confusion for those people who experience deficiencies in their ability to distinguish certain colors. When the colors in a particular image are converted so as to make them perceivable to color vision deficient people, most of the existing methods correct all the colors of the image instead of only the specific colors that are confused. When ordinary people view the images converted using such techniques, they experience a significant difference in perception. To solve this problem, this study investigates the color perception of color vision deficient people through analysis of confused color regions in images and proposes a new method that corrects the minimum number of color regions into optimal colors. For this purpose, the proposed method builds a confusion line database for colors confused by color vision deficient people using the CIEDE2000 color-difference formula and Brettel's method for simulation of color vision deficiency in the offline stage. In the online processing stage, regions are divided through the region growing technique, and the colors in the divided images are compared. When there exist confused colors by color vision deficient people, a method for finding the optimal color is proposed through the confusion line database. Furthermore, this study developed an optimization index to propose a method of finding such optimal colors and validated them through various tests. The excellence of the color correction results of this study was demonstrated based on an objective index as well as on participants' subjective visual perception through comparative experiments with other existing studies.