Computer access for persons who are blind or visually impaired: human factors issues

Suitably adapted computers hold considerable potential for integrating people who are blind or visually impaired into the mainstream. The principal problems that preclude the achievement of this potential are human factors issues. These issues are discussed, and the problems presented by icon-based interfaces are reviewed. An argument is offered that these issues, which ostensibly pertain to the blind or visually impaired user, are fundamental issues confronting all users. There is reason to hope that the benefits of research into the human factors issues of people with vision impairments will also extend to the sighted user.     

Fast Component-Based QR Code Detection in Arbitrarily Acquired Images

Quick Response (QR) codes are a type of 2D barcode that is becoming very popular, with several application possibilities. Since they can encode alphanumeric characters, a rich set of information can be made available through encoded URL addresses. In particular, QR codes could be used to aid visually impaired and blind people to access web based voice information systems and services, and autonomous robots to acquire context-relevant information. However, in order to be decoded, QR codes need to be properly framed, something that robots, visually impaired and blind people will not be able to do easily without guidance. Therefore, any application that aims assisting robots or visually impaired people must have the capability to detect QR codes and guide them to properly frame the code. A fast component-based two-stage approach for detecting QR codes in arbitrarily acquired images is proposed in this work. In the first stage, regular components present at three corners of the code are detected, and in the second stage geometrical restrictions among detected components are verified to confirm the presence of a code. Experimental results show a high detection rate, superior to 90 %, at a fast speed compatible with real-time applications.     

Contrasting usability evaluation methods with blind users

Usability tests are a part of user-centered design. Usability testing with disabled people is necessary, if they are among the potential users. Several researchers have already investigated usability methods with sighted people. However, research with blind users is insufficient, for example, due to different knowledge on the use of assistive technologies and the ability to analyze usability issues from inspection of non-visual output of assistive devices. From here, the authors aspire to extend theory and practice by investigating four usability methods involving the blind, visually impaired and sighted people. These usability methods comprise of local test, synchronous remote test, tactile paper prototyping and computer-based prototyping. In terms of effectiveness of evaluation and the experience of participants and the facilitator, local tests were compared with synchronous remote tests and tactile paper prototyping with computer-based prototyping. Through the comparison of local and synchronous remote tests, it has been found that the number of usability problems uncovered in different categories with both approaches was comparable. In terms of task completion time, there is a significant difference for blind participants, but not for the visually impaired and sighted. Most of the blind and visually impaired participants prefer the local test. As for the comparison of tactile paper prototyping and computer-based prototyping, it has been revealed that tactile paper prototyping provides a better overview of an application while the interaction with computer-based prototypes is closer to reality. Problems regarding the planning and conducting of these methods as they arise in particular with blind people were also discussed. Based on the authors’ experiences, recommendations were provided for dealing with these problems from both the technical and the organization perspectives.     

Assisting Visually Impaired People to Acquire Targets on a Large Wall-Mounted Display

Large displays have become ubiquitous in our everyday lives, but these displays are designed for sighted people.This paper addresses the need for visually impaired people to access targets on large wall-mounted displays. We developed an assistive interface which exploits mid-air gesture input and haptic feedback, and examined its potential for pointing and steering tasks in human computer interaction（HCI）. In two experiments, blind and blindfolded users performed target acquisition tasks using mid-air gestures and two different kinds of feedback（i.e., haptic feedback and audio feedback）. Our results show that participants perform faster in Fitts＇ law pointing tasks using the haptic feedback interface rather than the audio feedback interface. Furthermore, a regression analysis between movement time（MT） and the index of difficulty（ID）demonstrates that the Fitts＇ law model and the steering law model are both effective for the evaluation of assistive interfaces for the blind. Our work and findings will serve as an initial step to assist visually impaired people to easily access required information on large public displays using haptic interfaces.     

Automated interpretation and accessible presentation of technical diagrams for blind people

The EU-supported TeDUB (Technical Drawings Understanding for the Blind) project is developing a software system that aims to make technical diagrams accessible to blind and visually impaired people. It consists of two separate modules: one that analyses drawings either semi-automatically or automatically, and one that presents the results of this analysis to blind people and allows them to interact with it. The system is capable of analysing and presenting diagrams from a number of formally defined domains. A diagram enters the system as one of two types: first, diagrams contained in bitmap images, which do not explicitly contain the semantic structure of their content and thus have to be interpreted by the system, and second, diagrams obtained in a semantically enriched format that already yields this structure. The TeDUB system provides blind users with an interface to navigate and annotate these diagrams using a number of input and output devices. Extensive user evaluations have been carried out and an overall positive response from the participants has shown the effectiveness of the approach.     

Text entry for the Blind on Smartwatches

Universal Access in the Information Society - The interaction challenges presented by touch-screen enabled devices for blind and visually impaired people has been addressed extensively in the...     

An improved Web search engine for visually impaired users

The Google search engine was studied as a Web prototype to be modified and improved for blind users. A Specialized Search Engine for the Blind (SSEB) was developed with an accessible interface and improved functions (searching assistance functions, user-centered functions, and specialized design for the blind). An experiment was conducted with twelve participants, both blind and sighted, to verify the effects of SSEB. The performance was better with the SSEB than with the Google search engine, and the participants also showed higher satisfactions with the SSEB. Interface considerations for designing an accessible Web site for blind users are important. The users of SSEB could in the future be expanded to include most, if not all, visually impaired people, since the World Wide Web and all Internet resources should ideally be accessible to everyone.     

Blind-friendly user interfaces – a pilot study on improving the accessibility of touchscreen interfaces

Multimedia Tools and Applications - Touchscreen devices such as a smartphone, smartwatch, and tablets are essential assistive devices for visually impaired and blind people in performing activities...     

A novel multimodal interface for improving visually impaired people’s web accessibility

This paper introduces a novel interface designed to help blind and visually impaired people to explore and navigate on the Web. In contrast to traditionally used assistive tools, such as screen readers and magnifiers, the new interface employs a combination of both audio and haptic features to provide spatial and navigational information to users. The haptic features are presented via a low-cost force feedback mouse allowing blind people to interact with the Web, in a similar fashion to their sighted counterparts. The audio provides navigational and textual information through the use of non-speech sounds and synthesised speech. Interacting with the multimodal interface offers a novel experience to target users, especially to those with total blindness. A series of experiments have been conducted to ascertain the usability of the interface and compare its performance to that of a traditional screen reader. Results have shown the advantages that the new multimodal interface offers blind and visually impaired people. This includes the enhanced perception of the spatial layout of Web pages, and navigation towards elements on a page. Certain issues regarding the design of the haptic and audio features raised in the evaluation are discussed and presented in terms of recommendations for future work.     

面向盲人的图形显示设计方法及其用户体验研究

针对已有的盲人触觉显示器所展示的图像不能有效地为视觉残障人士提供准确的信息的问题,从盲人对电子触觉图像的需求出发,通过分析盲人在使用传统触觉图像中所遇问题以及涉及到的人机因素的相关背景知识,结合新型显示方案的需求,总结并提出盲人触觉图像设计准则.通过实验对比传统图像与根据该准则重新设计的T-图像,实验结果表明,T-图像...     

Microprocessor devices to lower the barriers for the blind and visually impaired

The university-based Working Group on Rehabilitation Engineering (called FORTec) is dedicated to research and development in the field of technical aids for disabled persons. During the last few years, several assistive devices for the blind and visually impaired have been developed. In this paper, three projects of particular scientific and practical relevance will be described: ColorTest—a speech output colour probe for the blind and colour blind. NotaPhon—a braille-input/speech-output note-taker and communication device for the blind. IRIS—an infrared operated information and orientation system for the blind and visually impaired.     

Image-Based Tactile Emojis: Improved Interpretation of Message Intention and Subtle Nuance for Visually Impaired Individuals

To enhance missing nonverbal cues in computer-mediated communication using text, those who can see often use emojis or emoticons. Although emojis for the sighted have transformed throughout the years to animated forms and added sound effects, emojis for visually impaired people remain underdeveloped. This study tested how tactile emojis based on visual imagery combined with the Braille system can enhance clarity in the computer-mediated communication environment for those with visual impairments. Results of this study confirmed three things: Visually impaired subjects were able to connect emotional emojis to the emotion they represented without any prior guidance, image-based (picture-based) and non-image-based (abstraction-based) tactile emoji were equally learnable, and the clarity of intended meaning was improved when an emoji was used with text (Braille). Thirty visually impaired subjects were able to match an average of 67% of emotions without prior guidance, and three of the four subjects who matched perfectly both before and after guidance were congenitally blind. The subjects had the most trouble discriminating the facial feature of “fear” between “sadness” or “surprised” for they shared similar traits. After guidance, the image-based tactile design elicited an average of 81% correct answers, whereas the non-image-based tactile design elicited an average of 37%, showing that the image-based tactile design was more effective for learning the meaning of emojis. The clarity of the sentence was also improved. This study shows that image-based tactile emojis can improve the texting experience of visually impaired individuals to a level where they can communicate subtle emotional cues through tactile imagery. This advance could minimize the service gap between sighted and visually impaired people and offer a much more abundant computer-mediated communication environment for visually impaired individuals.     

视听触同步刺激的数字化盲文学习方法

盲文是视障人士获取信息,学习知识的重要媒介.然而,目前基于纸质书籍的盲文学习方法只能提供盲文点位的触觉刺激,存在不便携、不易用且内容陈旧等问题.为此,本文提出了一种视觉、听觉和触觉同步刺激的数字化盲文学习方法,能够提高视障人士的盲文学习效率.基于多感知盲文学习机,本文设计了一种多感知信息匹配算法,能够输出文字、声音和盲文点位相同内容的信息,为视障人士无障碍学习盲文提供条件.短期记忆的盲文学习效果实验表明:(1)在视觉、听觉和触觉的共同刺激下,盲文学习效率最高,即在盲文学习过程中,增加视觉刺激对于视力残余人士提升盲文学习效率有显著正向促进作用;(2)在听觉和触觉的共同刺激下,盲文学习效率并不高,即全盲人士学会盲文有一定难度,需要有较长的学习曲线;(3)仅在听觉刺激下,盲文学习效率很低,即开发语音学盲文的APP不具备实践意义.     

Virtual Senses

Products-to-be include Touch Color, a thermal digital device that lets visually impaired people visualize works of art by touch; Smart Cane, which combines with an ultrasonic sensor to help blind people navigate paths; glasses that measure time between blinks; virtual pets; and a device that uses sensors to smell.     

Assisting people with visual impairments in aiming at a target on a large wall-mounted display

Large interactive displays have become ubiquitous in our everyday lives, but these displays are designed for the needs of sighted people. In this paper, we specifically address assisting people with visual impairments to aim at a target on a large wall-mounted display. We introduce a novel haptic device, which explores the use of vibrotactile feedback in blind user search strategies on a large wall-mounted display. Using mid-air gestures aided by vibrotactile feedback, we compared three target-aiming techniques: Random (baseline) and two novel techniques – Cruciform and Radial. The results of our two experiments show that visually impaired participants can find a target significantly faster with the Cruciform and Radial techniques than with the Random technique. In addition, they can retrieve information on a large display about twice as fast by augmenting speech feedback with haptic feedback in using the Radial technique. Although a large number of studies have been done on assistive interfaces for people who have visual impairments, very few studies have been done on large vertical display applications for them. In a broader sense, this work will be a stepping-stone for further research on interactive large public display technologies for users who are visually impaired.     

Interactivity Improves Usability of Geographic Maps for Visually Impaired People

Tactile relief maps are used by visually impaired people to acquire mental representation of space, but they retain important limitations (limited amount of information, braille text, etc.). Interactive maps may overcome these limitations. However, usability of these two types of maps has never been compared. It is then unknown whether interactive maps are equivalent or even better solutions than traditional raised-line maps. This study presents a comparison of usability of a classical raised-line map versus an interactive map composed of a multitouch screen, a raised-line overlay, and audio output. Both maps were tested by 24 blind participants. We measured usability as efficiency, effectiveness, and satisfaction. Our results show that replacing braille with simple audio-tactile interaction significantly improved efficiency and user satisfaction. Effectiveness was not related to the map type but depended on users’ characteristics as well as the category of assessed spatial knowledge. Long-term evaluation of acquired spatial information revealed that maps, whether interactive or not, are useful to build robust survey-type mental representations in blind users. Altogether, these results are encouraging as they show that interactive maps are a good solution for improving map exploration and cognitive mapping in visually impaired people.     

Fuzzy Free Path Detection from Disparity Maps by Using Least-Squares Fitting to a Plane

A method to detect obstacle-free paths in real-time which works as part of a cognitive navigation aid system for visually impaired people is proposed. It is based on the analysis of disparity maps obtained from a stereo vision system which is carried by the blind user. The presented detection method consists of a fuzzy logic system that assigns a certainty to be part of a free path to each group of pixels, depending on the parameters of a planar-model fitting. We also present experimental results on different real outdoor scenarios showing that our method is the most reliable in the sense that it minimizes the false positives rate.     

Artificial intelligence for visually impaired

The eyes are an essential tool for human observation and perception of the world, helping people to perform their tasks. Visual impairment causes many inconveniences in the lives of visually impaired people. Therefore, it is necessary to focus on the needs of the visually impaired community. Researchers work from different angles to help visually impaired people live normal lives. The advent of the digital age has profoundly changed the lives of the visually impaired community, making life more convenient. Deep learning, as a promising technology, is also expected to improve the lives of visually impaired people. It is increasingly being used in the diagnosis of eye diseases and the development of visual aids. The earlier accurate diagnosis of the eye disease by the doctor, the sooner the patient can receive the appropriate treatment and the better chances of a cure. This paper summarises recent research on the development of artificial intelligence-based eye disease diagnosis and visual aids. The research is divided according to the purpose of the study into deep learning methods applied in diagnosing eye diseases and smart devices to help visually impaired people in their daily lives. Finally, a summary is given of the directions in which artificial intelligence may be able to assist the visually impaired in the future. In addition, this overview provides some knowledge about deep learning for beginners. We hope this paper will inspire future work on the subjects..     

The disability index analysis system via an ergonomics, expert systems, and multiple attribute decision-making process

Through rehabilitation and training, visually impaired people can be placed in types of jobs that are compatible with their abilities. A functional assessment approach should be established to measure the physical ability of handicapped people in response to specific tasks and environmental demands. The objective of this study is to develop an integrated computerized system, entitled VITAL (Vision Impaired Task and Assignment Lexicon), to measure the vision impaired worker's residual capabilities and to provide the necessary recommendations for job accommodations. VITAL includes two major modules: the disability index, and the ergonomics consultation module. A single measure, the Disability Index (DI), which represents capacities of vision impaired individuals through a range of skill tests is developed via Multiple Attribute Decision Making (MADM) procedures. The resulting DI can be used in identifying the functional deficits and limitations of the visually impaired worker, and matching the visually impaired people to appropriate employment. This information is also used in the ergonomic consultation module to provide recommendations regarding job and workplace design for the vision impaired worker.     

Haptic技术在盲人空间认知和导航服务中应用研究进展

基于震动(Haptic)的盲人导航服务开发与研制对于视力受损者有辅助引导、提高生活质量的作用.归纳了盲人的空间认知理论研究,尝试构建了盲人的空间认知理论框架,解释盲人在中小尺度下对地理环境的认知情况.梳理近些年来盲人基于Haptic的导航器具的研究,发现现有盲人导航系统出现了蓬勃发展的势头,从技术层面解决了盲人的出行需求,但是在理论层面和实际应用层面仍面临巨大挑战,现有导航技术提供的服务与盲人的现实需求仍存在一定的差距.