Testing and Improving an Optimization-Based Digital Colorblindness Corrective Filter

Computers often communicate essential information via color which is lost to colorblind users. In order to address this information loss, designers and computer scientists have created a variety of different correction methods to improve computer accessibility. One such method was created by Luke Jefferson and Richard Harvey in their 2006 paper, “Accommodating Color Blind Computer Users” which consists of a difference histogram, differences of key colors, optimization and interpolation to adjust images for specific types of congenital colorblindness. I have recreated their algorithm as well as their original test images. I then conducted extensive tests on challenging images to examine the strengths and weaknesses of the algorithm. Finally, I further improved the algorithm in an effort to determine if this method might be useful for a real-time corrective filter

Adaptação de cor para dicromatas na visualização de imagens

The increasing use of visual information in the new media brought to the color a new and relevant role. Inter alia, the color is fundamental in discriminating the contents, providing the global understanding of things. However, some people have a visual impairment designated color vision defective (CVD), which restrains the vision of color in a proper way, so compromising the correct perception of the visual contents. In order to overcome the referred handicap, on this article is proposed an algorithm which can be used to adapt the color to dichromats to improving the way they see the images. Consequently, the images become more readable and the discernment and comprehension of its components is enhanced

Adaptação da cor da tipografia páginas web para pessoas com deficit na visão da cor

A legibilidade do texto é fundamental à sua leitura, sendo para isso determinante o contraste entre as cores usadas para a tipografia e para o fundo. Ainda que a escolha das cores seja adequada, o contraste pode ser insuficiente quando a tipografia é observada por pessoas com deficit na visão da cor, comprometendo assim a legibilidade. Sendo que é significativa a taxa de incidência do deficit na visão da cor, correntemente conhecido por daltonismo, assim como o índice de utilização da web pela população em geral, onde é frequente a existência de blocos de texto - com recurso à cor para tipografia e para o fundo-, são frequentes as situações em que se torna difícil uma leitura adequada, limitando o acesso à mensagem escrita. Neste contexto, este artigo vem propor um método para melhoria das condições de visualização dos blocos de texto, que passa pela aplicação de um algoritmo de adaptação, que efetua a alteração da cor da tipografia para preto ou para branco, dependendo da forma como a cor de fundo é vista pela daltónico. Dessa forma, é incrementado o contraste e é proporcionada uma integral acessibilidade aos conteúdos tipográficos

The Distance between Colors; Using DeltaE* to Determine Which Colors Are Compatible

The focus of this study was to identify colors that can be easily distinguished from one another by normal color vision and slightly deficient color vision observers, and then test those colors to determine the significance of color separation as an indicator of color discriminability for both types of participants. There were 14 color normal and 9 color deficient individuals whose level of color deficiency were determined using standard diagnostic tests. The colors were selected by avoiding co-linearity in the color confusion line graphs for deuteranopes, protanopes and tritanopes. The difference between each of the colors was then calculated. The chosen colors were presented to the participants in a Color Vision Discrimination (CVD) test, first as color boxes and then as color text made up of three letters followed by three numbers. A one-tailed Spearman\u27s non-parametric Rank Order Correlation was conducted. The results indicated that the difference between two colors does not determine the ability of a color normal observer to distinguish between two colors given that the color is presented as a color block ( rs = -.260, p = .234), but does determine their ability when presented as color text (rs = -.644, p = .001). When it comes to color deficient individuals, the results show that for color blocks (rs = -.558, p = .015) and color text (rs = -.505, p = .002) their ability to distinguish between the candidate colors depends on the separation between the colors. Colors were selected on the basis that they were not confused with any other color. Those colors found to be most easily distinguished will be useful in many different applications such as web site design, Internet displays of all types, and various other military and industrial applications

Data visualisation literacy in higher education: an exploratory study of understanding of a learning dashboard tool

The visualisation of data has become ubiquitous. Visualisations are used to represent data in a way that is easy to understand and useful in our lives. Each data visualisation needs to be suitable to extract the correct information to complete a task and make an informed decision while minimising the impact of biases. To achieve this, the ability to create and read visualisations has become as important as the ability to read and write. Therefore, the Information Visualisation community is applying more attention to literacy and decision making in data visualisations. Until recently, researchers lacked valid and reliable test instruments to measure the literacy of users or the taxonomy to detect biased judgement in data visualisations. A literature review showed there is relatively little research on data visualisations for different user data literacy levels in authentic settings and a lack of studies that provide evidence for the presence of cognitive biases in data visualisations. This exploratory research study was undertaken to develop a method to assess perceived usefulness and confidence in reporting dashboards within higher education by adapting existing research instruments. A survey was designed to test perceived usefulness, perceived skill and 24 multiple-choice test items covering six data visualisations based on eight tasks. The study was sent to 157 potential participants, with a response rate of 20.38%. The results showed data visualisations are useful, but the purpose of some data visualisations is not always understood. Also, we showed there is a consensus that respondents perceive their data visualisation literacy is higher than they believe their peers to be. However, the higher their overconfidence, the lower their actual data visualisation literacy score. Finally, we discuss the benefits, limitations and possible future research areas

Assessing Color Discrimination

The purpose of this study was to evaluate human color vision discriminability within individuals that have color normal vision and those that have color deficient vision. Combinations of 15 colors were used from a list of colors recommended for computer displays in Air Traffic Control settings, a population with some mildly color vision deficient individuals. After a match to sample test was designed to assess the limits of human color vision discrimination based on color saturation and hue, standard color diagnostic tests were used to categorize college students as having normal or deficient color vision. The results argue that color saturation and hue impact human ability to discriminate colors, particularly as the delta E is small. This evidence also indicates that the effect that hue and saturation have on discriminability is not predicted by standard color vision assessment tests. Our results show that there is no difference in discriminability based on hue or saturation of both color normal and color deficient individuals, but for one exception. The delta e for black was significantly higher than all other colors. This was true for both color normal and color deficient individuals. From this information, it can be determined that the tolerance threshold for black should be dE(00) = 36.9 and the tolerance for all other colors to be dE(00) =9.2 for display on LCD displays. These results will have value for any computer display of critical information in which color discrimination is important for complete comprehension. The large number of individuals with color vision problems also makes these results a useful guide to color coding of information on web page design

Recoloração de imagens para dicromatas baseada em mapas elásticos

TCC(graduação) - Universidade Federal de Santa Catarina. Campus Araranguá. Engenharia da Computação.A deficiência na percepção de cores (DPC) afeta 8% da população caucasiana masculina, causada pela falha ou ausência de células fotorreceptoras do tipo cone na retina, e proveniente de causa genética, alguma lesão no olho, ou também devido a outras doenças, como diabetes, leucemia, etc. O indivíduo com DPC tem dificuldades na percepção de cores, que variam dependendo do tipo de deficiência. Dicromatas são os indivíduos com DPC causada pela ausência de um dos tipos de fotorreceptores cone, causando dificuldades na percepção das cores. A DPC causa dificuldades na realização de tarefas que necessitam da distinção de cores, o que pode prejudicar o indivíduo tanto na vida pessoal quanto profissional. Este trabalho propõe uma técnica de recoloração de imagens para dicromatas baseada na técnica de redução de dimensionalidade Mapas Elásticos, onde o objetivo é proporcionar aos indivíduos imagens que preservam detalhes da imagem original, como contrastes entre cores, os quais, os dicromatas não percebem. A técnica foi implementada tanto para CPU como para GPU, apresentando bons tempos de execução, além de apresentar bons resultados no aspecto da preservação de contrastes após a recoloração, a técnica também se propõe a preservar o aspecto de naturalidade da imagem, escolhendo o mapeamento final que minimiza a soma total das distância entre a cor original e o mapeamento dela no plano de percepção dos dicromatas.Color Vision Deficiency (CVD) affects 8% of caucasian male populations, caused by failure or absence of cone-like photorreceptor cells in the retina. CVD may be from genetic cause, some eye injury, or from other diseases such as diabetes, leukemia, etc. Individuals with CVD have difficulty in color perception, whose variation depends on the type of disability. Dichromats are individuals with CVD caused by the abscence of one of the types of cone photoreceptors, causing difficulties in the perception of colors. CVD causes difficulties in performing tasks that require color distinction, which can harm the individual in both personal and professional life. This work proposes an image recoloring technique for dichromats based on the Elastic Maps dimensionality reduction technique, where the objective is to provide images that preserve details of the original image, such as color contrasts. The technique was implemented both CPU and GPU, presenting good execution times, and good results in the aspect of preservation of contrasts after recoloring, the technique also proposes to preserve the aspect of naturality of image, choosing the final mapping that minimizes the total sum of the distance between the original color and the mapping of it in the plane of dichromat perception

Desenvolvimento de aplicativo móvel para auxílio de indivíduos com discromatopsia utilizando visão computacional

Trabalho de Conclusão de Curso (graduação)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Ciência da Computação, 2018.Daltonismo é uma deficiência visual não tão rara, visto que aproximadamente 8% da população mundial masculina a possui, que dificulta o indivíduo na distinção de determinadas cores, de acordo com o tipo de daltonismo. Este trabalho propõe uma ferramenta que possa, além de auxiliar indivíduos daltônicos no seu cotidiano a identificar objetos que possuem alguma cor na qual o indivíduo não consiga distingui-la, permitir que qualquer indivíduo com acesso a esta ferramenta descubra se possui ou não daltonismo de uma maneira rápida e eficiente. É proposta, então, a criação de um aplicativo para dispositivos móveis, permitindo maior acessibilidade e visando uma fácil adaptação para futuramente ser utilizado em óculos inteligentes, sendo que o aplicativo é calibrado por meio das imagens do teste de daltonismo mais utilizado no mundo, o teste de Ishihara.Color blindness is a not so rare visual deficiency, since nearly 8% of the male world population is colorblind, which makes it dificult for the individual distinguish certain colors, according to the type of color blindness. This work proposes a tool that can, in addition to help colorblind people in their daily lives to identify objects that have some color in which they can’t distinguish it, allow any person with access to this tool to find out whether or not they have color blindness in a fast and efficient way. Then it is proposed to develop a mobile app, allowing greater accessibility and aiming for an easy adaptation to this metdology be used, in the future, in smart glasses, being that the application is calibrated through the images of the most used color blindness test in the world, the Ishihara test