609 research outputs found
Personalizable edge services for Web accessibility
Web Content Accessibility guidelines by W3C (W3C Recommendation, May 1999. http://www.w3.org/TR/WCAG10/) provide several suggestions for Web designers regarding how to author Web pages in order to make them accessible to everyone. In this context, this paper proposes the use of edge services as an efficient and general
solution to promote accessibility and breaking down the
digital barriers that inhibit users with disabilities to actively
participate to any aspect of society. The idea behind edge
services mainly affect the advantages of a personalized navigation in which contents are tailored according to different issues, such as client’s devices capabilities, communication systems and network conditions and, finally, preferences and/or abilities of the growing number of users that access the Web. To meet these requirements, Web designers have to efficiently provide content adaptation and
personalization functionalities mechanisms in order to guarantee universal access to the Internet content. The so far dominant paradigm of communication on theWWW, due to its simple request/responsemodel, cannot efficiently address such requirements. Therefore, it must be augmented with new components that attempt to enhance the scalability, the performances and the ubiquity of the Web. Edge servers, acting on the HTTP data flow exchanged between client and server, allow on-the-fly content adaptation as well as other complex functionalities beyond the traditional caching and content replication services. These value-added services are called edge services and include personalization and customization, aggregation from multiple sources, geographical personalization of the navigation of pages (with
insertion/emphasis of content that can be related to the user’s
geographical location), translation services, group navigation and awareness for social navigation, advanced services for bandwidth optimization such as adaptive compression and format transcoding, mobility, and ubiquitous access to Internet content. This paper presents Personalizable Accessible Navigation (PAN) that is a set of edge services designed to improveWeb pages accessibility, developed and deployed on top of a programmable intermediary framework. The characteristics and the location of the services,
i.e., provided by intermediaries, as well as the personalization and the opportunities to select multiple profiles make PAN a platform that is especially suitable for accessing the Web seamlessly also from mobile terminals
A novel intermediary framework for dynamic edge service composition
Multimedia content, user mobility and heterogeneous client devices require novel systems that are able to support ubiquitous access to the Web resources. In this scenario, solutions that combine flexibility, efficiency and scalabilityin offering edge services for ubiquitous access are needed. We propose an original intermediary framework, namely Scalable Intermediary Software Infrastructure (SISI), which is able to dynamically compose edge services on the basis of user preferences and device characteristics. The SISI framework exploits a per-user profiling mechanism, where each user can initiallyset his/her personal preferences through a simple Web interface, and the system is then able to compose at run-time the necessary components. The basic framework can be enriched through new edge services that can be easily implemented through a programming model based on APIs and internal functions. Our experiments demonstrate that flexibility and edge service composition do not affect the system performance. We show that this framework is able to chain multiple edge services and to guarantee stable performance
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
Adaptive Methods for Color Vision Impaired Users
Color plays a key role in the understanding of the information in computer environments. It
happens that about 5% of the world population is affected by color vision deficiency (CVD),
also called color blindness. This visual impairment hampers the color perception, ending up by
limiting the overall perception that CVD people have about the surrounding environment, no
matter it is real or virtual. In fact, a CVD individual may not distinguish between two different
colors, what often originates confusion or a biased understanding of the reality, including web
environments, whose web pages are plenty of media elements like text, still images, video,
sprites, and so on.
Aware of the difficulties that color-blind people may face in interpreting colored contents,
a significant number of recoloring algorithms have been proposed in the literature with the
purpose of improving the visual perception of those people somehow. However, most of those
algorithms lack a systematic study of subjective assessment, what undermines their validity, not
to say usefulness. Thus, in the sequel of the research work behind this Ph.D. thesis, the central
question that needs to be answered is whether recoloring algorithms are of any usefulness and
help for colorblind people or not.
With this in mind, we conceived a few preliminary recoloring algorithms that were published in
conference proceedings elsewhere. Except the algorithm detailed in Chapter 3, these conference
algorithms are not described in this thesis, though they have been important to engender
those presented here. The first algorithm (Chapter 3) was designed and implemented for people
with dichromacy to improve their color perception. The idea is to project the reddish hues onto
other hues that are perceived more regularly by dichromat people.
The second algorithm (Chapter 4) is also intended for people with dichromacy to improve their
perception of color, but its applicability covers the adaptation of text and image, in HTML5-
compliant web environments. This enhancement of color contrast of text and imaging in web
pages is done while keeping the naturalness of color as much as possible. Also, to the best of our
knowledge, this is the first web recoloring approach targeted to dichromat people that takes
into consideration both text and image recoloring in an integrated manner.
The third algorithm (Chapter 5) primarily focuses on the enhancement of some of the object
contours in still images, instead of recoloring the pixels of the regions bounded by such contours.
Enhancing contours is particularly suited to increase contrast in images, where we find adjacent
regions that are color indistinguishable from dichromat’s point of view. To our best knowledge,
this is one of the first algorithms that take advantage of image analysis and processing techniques
for region contours.
After accurate subjective assessment studies for color-blind people, we concluded that the CVD
adaptation methods are useful in general. Nevertheless, each method is not efficient enough to
adapt all sorts of images, that is, the adequacy of each method depends on the type of image
(photo-images, graphical representations, etc.).
Furthermore, we noted that the experience-based perceptual learning of colorblind people
throughout their lives determines their visual perception. That is, color adaptation algorithms must satisfy requirements such as color naturalness and consistency, to ensure that dichromat
people improve their visual perception without artifacts. On the other hand, CVD adaptation
algorithms should be object-oriented, instead of pixel-oriented (as typically done), to select
judiciously pixels that should be adapted. This perspective opens an opportunity window for
future research in color accessibility in the field of in human-computer interaction (HCI).A cor desempenha um papel fundamental na compreensão da informação em ambientes computacionais.
Porém, cerca de 5% da população mundial é afetada pela deficiência de visão de
cor (ou Color Vision Deficiency (CVD), do Inglês), correntemente designada por daltonismo. Esta
insuficiência visual dificulta a perceção das cores, o que limita a perceção geral que os indivíduos
têm sobre o meio, seja real ou virtual. Efetivamente, um indivíduo com CVD vê como iguais
cores que são diferentes, o que origina confusão ou uma compreensão distorcida da realidade,
assim como dos ambientes web, onde existe uma abundância de conteúdos média coloridos,
como texto, imagens fixas e vídeo, entre outros.
Com o intuito de mitigar as dificuldades que as pessoas com CVD enfrentam na interpretação de
conteúdos coloridos, tem sido proposto na literatura um número significativo de algoritmos de
recoloração, que têm como o objetivo melhorar, de alguma forma, a perceção visual de pessoas
com CVD. Porém, a maioria desses trabalhos carece de um estudo sistemático de avaliação
subjetiva, o que põe em causa a sua validação, se não mesmo a sua utilidade. Assim, a principal
questão à qual se pretende responder, como resultado do trabalho de investigação subjacente
a esta tese de doutoramento, é se os algoritmos de recoloração têm ou não uma real utilidade,
constituindo assim uma ajuda efetiva às pessoas com daltonismo.
Tendo em mente esta questão, concebemos alguns algoritmos de recoloração preliminares que
foram publicados em atas de conferências. Com exceção do algoritmo descrito no Capítulo 3,
esses algoritmos não são descritos nesta tese, não obstante a sua importância na conceção
daqueles descritos nesta dissertação. O primeiro algoritmo (Capítulo 3) foi projetado e implementado
para pessoas com dicromacia, a fim de melhorar a sua perceção da cor. A ideia consiste
em projetar as cores de matiz avermelhada em matizes que são melhor percebidos pelas pessoas
com os tipos de daltonismo em causa.
O segundo algoritmo (Capítulo 4) também se destina a melhorar a perceção da cor por parte de
pessoas com dicromacia, porém a sua aplicabilidade abrange a adaptação de texto e imagem,
em ambientes web compatíveis com HTML5. Isto é conseguido através do realce do contraste
de cores em blocos de texto e em imagens, em páginas da web, mantendo a naturalidade da
cor tanto quanto possível. Além disso, tanto quanto sabemos, esta é a primeira abordagem de
recoloração em ambiente web para pessoas com dicromacia, que trata o texto e a imagem de
forma integrada.
O terceiro algoritmo (Capítulo 5) centra-se principalmente na melhoria de alguns dos contornos
de objetos em imagens, em vez de aplicar a recoloração aos pixels das regiões delimitadas por
esses contornos. Esta abordagem é particularmente adequada para aumentar o contraste em
imagens, quando existem regiões adjacentes que são de cor indistinguível sob a perspetiva dos
observadores com dicromacia. Também neste caso, e tanto quanto é do nosso conhecimento,
este é um dos primeiros algoritmos em que se recorre a técnicas de análise e processamento de
contornos de regiões.
Após rigorosos estudos de avaliação subjetiva com pessoas com daltonismo, concluiu-se que os
métodos de adaptação CVD são úteis em geral. No entanto, cada método não é suficientemente
eficiente para todos os tipo de imagens, isto é, o desempenho de cada método depende do tipo de imagem (fotografias, representações gráficas, etc.).
Além disso, notámos que a aprendizagem perceptual baseada na experiência das pessoas daltónicas
ao longo de suas vidas é determinante para perceber aquilo que vêem. Isto significa que os
algoritmos de adaptação de cor devem satisfazer requisitos tais como a naturalidade e a consistência
da cor, de modo a não pôr em causa aquilo que os destinatários consideram razoável
ver no mundo real. Por outro lado, a abordagem seguida na adaptação CVD deve ser orientada
aos objetos, em vez de ser orientada aos pixéis (como tem sido feito até ao momento), de
forma a possibilitar uma seleção mais criteriosa dos pixéis que deverão ser sujeitos ao processo
de adaptação. Esta perspectiva abre uma janela de oportunidade para futura investigação em
acessibilidade da cor no domínio da interacção humano-computador (HCI)
Impaired Vision Simulation
We designed, developed, and tested Unseeable, a browser game with the goal of having non-colorblind individuals experience the perspective of a colorblind person in order to increase empathy with them and recognize their daily struggles caused by their visual impairment. The game was developed using Three.js to build the game, node.js and express.js for the server, and MongoDB for the database used to store playtesting data
The New State of Surveillance: Societies of Subjugation
Foundational surveillance studies theory has largely been shaped in line with the experiences of white subjects in western capitalist societies. Formative scholars, most notably Michel Foucault and Gilles Deleuze, theorized that the advancement of surveillance technology tempers the State’s reliance on mass discipline and corporal punishment. Legal scholarship examining modern surveillance perpetuates this view, and popular interventions, such as the blockbuster docudrama The Social Dilemma and Shoshana Zuboff’s bestseller The Age of Surveillance Capitalism, mainstream the myth of colorblind surveillance. However, the experiences of nonwhite subjects of surveillance—pushed to or beyond the margins of these formative discourses—reflect otherwise.
By disrupting surveillance theory and pushing it beyond the white subject and the West, this Article introduces the “society of subjugation” as a rebuttal. First, society of subjugation theory demystifies the colorblind presumption that advancements in surveillance technology humanize the State’s administration of it by diminishing reliance on mass discipline and punishment. Second, this unchecked deployment of digital surveillance in authoritarian states is intended to subjugate minority groups marked as oppositional, a form of collective discipline and punishment that supersedes social control—as critical scholars examining racialized surveillance in the United States have argued. Through its focal case study of Uyghur surveillance in China, this Article analyzes how state administration of digital surveillance blurs the mandates of mass control, discipline, and punishment into a state ensemble of subjugation.
Further, this Article builds on surveillance literature by arguing that the salient locus of state surveillance may be racial identity, but, depending on the political context, may fixate on other forms of subaltern identity such as religion, sexual orientation, gender, and their intersections. In turn, this expands scholarly analysis and attention to other groups stigmatized by the rising tide and deepening gaze of digital surveillance—a phenomenon unfolding on a global scale
Designing Clarity: Utilizing Graphic Design to Enhance Media Functionality for the Visually Impaired
The designed purpose of this research is to help to bridge the gap between graphic design and those who suffer from color-blindness. By not only coming to a better understanding of color deficiencies but also rethinking how we approach our use of color within our designs, we may begin to create more inclusive designs, thus communicating more efficiently
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