Tactile graphic

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Tactile graphics, including tactile pictures, tactile diagrams, tactile maps, and tactile graphs, are images that use raised surfaces so that a visually impaired person can feel them. They are used to convey non-textual information such as maps, paintings, graphs and diagrams.

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Tactile graphics can be seen as a subset of accessible images. Images can be made accessible to the visually impaired in various ways, such as verbal description, sound, or haptic (tactual) feedback. One of the most common uses for tactile graphics is the production of tactile maps.

Tactile maps

Paper tactile map Disability5 200.jpg
Paper tactile map

The types and forms of tactile maps began with the oldest and most rudimentary or a mixed media format. This tactile map is produced by simply attaching objects to a substrate to represent different items or symbols. More recent tactile maps are produced by computers through different means such as an ink-jet printers.

Thermoform is one of the most common methods of producing tactile maps. This process is also known as vacuum forming. Thermoform maps or plans are created from a process where a sheet of plastic is heated and vacuumed on top of a model or master. The master can be made from many substances, although certain materials are more durable than others. Since this process involves creating a mold, it is somewhat time-consuming.

Swell paper has a special coating of heat-reactive chemicals. Microcapsules of alcohol implanted in the paper fracture when exposed to heat and make the surface of the paper inflate. Placing black ink on the paper prior to a heat process provides control over the raised surface areas. This type of map is not as robust as the Thermoform map, but can be produced with less effort and expense.

Modified Braille embossers can also be used to produce tactile paper maps. [1]

Ink-jet tactile maps are made by layering a specially designed ink. Each layer is cured by UV irradiation before the next layer is added. This technology is an offshoot of other industries, such as circuit board manufacturing and biomedical applications. [2]

The substrate for tactile maps is a very important attribute, since different materials can enhance or reduce legibility and durability. Several types of substrates can be used to produce a tactile map. These include rough and smooth plastic, rough and smooth paper, microcapsule paper, Braillon, and aluminum. Many factors should be considered when choosing a substrate; these include but are not limited to function, durability, and portability. [3]

Tactile map variables: Just as Jacques Bertin retinal variables help determine how visual maps are produced; tactile maps have a formula as well. Although researchers have not standardized tactile map variables, these nine are usually included depending on the substrate: vibration, flutter, pressure, temperature, size, shape, texture/grain, orientation, and elevation. [4]

Typical tactile elevations: Thermoformed maps usually have an elevation of at least 1mm. Swell Paper averages 0.5 mm and braille embossers have a range from 0.25–1 mm. Ink-jet printers can be controlled to vary elevation as needed. A (2009) study conducted by Sandra Jehoel tested various height levels and estimated that preferred tactile elevations fall between 40 and 80 micrometres depending on the substrate background, shape of the object and smoothness of lines. Symbols such as a triangle, square and a circle should have a minimum base line length of 6.4, 5.0 and 5.5 mm respectively for proper recognition. [5]

Audio tactile maps or graphic tablets are interactive devices. Electronic tactile talking touch pad instruments use Macromedia Flash software with audio files to convey information to the blind or visually impaired user. As the user's finger engages a feature or symbol a recording provides information about the object, symbol or area. For example, the sound of splashing water can be used for areas such as rivers or oceans. This format has great potential for transmitting information over the Internet which can be downloaded to a computer or hand-held device. [6]

A great deal of hardware already exists that can be used by the blind or visually impaired to interact with computer screen graphics. A vibrating mouse or other force feedback devices can be adapted to turn any visual software generated map into a hybrid tactile map. The interactive signal to a device can be varied when crossing a boundary or symbol. [7]

High resolution refreshable braille displays containing 1,500 to 12,000 pixels are already available in market. Graphic braille display available in the market is DV-2 (from KGS [8] ) with 1,536 pixels, Hyperbraille [9] with 7,200 pixels and TACTISPLAY Table/Walk (from Tactisplay Corp. [10] ) with 2,400/12,000 pixels respectively. TACTISPLAY table [11] has total 12,000 pixels arranged in 120x100.

Zoom maps are a recently developed tactile map. These maps are designed specifically for those who can read braille and have had no previous interaction with tactile maps. The term zoom is comparable to a zoom-able visual raster internet map. A country is divided into regions on the first map then the next zoomed map will have a breakdown of the regions and so forth until a city level is reached. These successive maps rely on a dependable texture as the map zoom progresses. This produces a familiarity as one zooms from the proceeding map. This is achieved in many instances with line orientation, area and consistent shape. The Braille text on the map is placed next to a rectangular textured legend for area identification. [12]

Related Research Articles

Braille Tactile writing system for blind and visually impaired people

Braille is a tactile writing system used by people who are visually impaired, including people who are blind, deafblind or who have low vision. It can be read either on embossed paper or by using refreshable braille displays that connect to computers and smartphone devices. Braille can be written using a slate and stylus, a braille writer, an electronic braille notetaker or with the use of a computer connected to a braille embosser.

Braille embosser Impact printer that renders text as tactile braille cells

A braille embosser is an impact printer that renders text as tactile braille cells. Using braille translation software, a document or digital text can be embossed with relative ease. This makes braille production efficient and cost-effective. Braille translation software may be free and open-sourced or paid.

Map Symbolic depiction of relationships between elements of some space

A map is a symbolic depiction emphasizing relationships between elements of some space, such as objects, regions, or themes.

Perkins Brailler

The Perkins Brailler is a "braille typewriter" with a key corresponding to each of the six dots of the braille code, a space key, a backspace key, and a line space key. Like a manual typewriter, it has two side knobs to advance paper through the machine and a carriage return lever above the keys. The rollers that hold and advance the paper have grooves designed to avoid crushing the raised dots the brailler creates.

An output device is any piece of computer hardware equipment which converts information into a human-perceptible form or, historically, into a physical machine-readable form for use with other non-computerized equipment. It can be text, graphics, tactile, audio, or video. Examples include monitors, printers, speakers, headphones, projectors, GPS devices, optical mark readers, and braille readers.

Deafblindness Condition of little or no useful sight and little or no useful hearing

Deafblindness is the condition of little or no useful hearing and little or no useful sight. Different degrees of vision loss and auditory loss occur within each individual, thus making the deafblind community unique with many types of deafblindness involved. Because of this inherent diversity, each deafblind individual's needs regarding lifestyle, communication, education, and work need to be addressed based on their degree of dual-modality deprivation, to improve their ability to live independently. In 1994, an estimated 35,000–40,000 United States residents were medically deafblind. Helen Keller was a well-known example of a deafblind individual. To further her lifelong mission to help the deafblind community to expand its horizons and gain opportunities, the Helen Keller National Center for Deaf-Blind Youths and Adults, with a residential training program in Sands Point, New York, was established in 1967 by an act of Congress.

Tactile signing is a common means of communication used by people with deafblindness. It is based on a sign language or another system of manual communication.

Canadian currency tactile feature Feature on the Canadian Journey and Frontier series of Canadian banknotes

The Canadian currency tactile feature is a feature on the Canadian Journey and Frontier series of Canadian banknotes to aid people who are visually impaired to identify the notes. The feature indicates the banknote denomination in the upper left corner of the face side of the bill using a series of raised dots. It was suggested by Bruno Thériault, an administrator for the Canadian National Institute for the Blind, and designed by Susan Lederman, a professor of psychology at Queen's University.

Sensory substitution is a change of the characteristics of one sensory modality into stimuli of another sensory modality.

Visual impairment, also known as vision impairment, is a medical definition primarily measured based on an individual's better eye visual acuity; in the absence of treatment such as correctable eyewear, assistive devices, and medical treatment– visual impairment may cause the individual difficulties with normal daily tasks including reading and walking. Low vision is a functional definition of visual impairment that is chronic, uncorrectable with treatment or correctable lenses, and impacts daily living. As such low vision can be used as a disability metric and varies based on an individual's experience, environmental demands, accommodations, and access to services. The American Academy of Ophthalmology defines visual impairment as the best-corrected visual acuity of less than 20/40 in the better eye, and the World Health Organization defines it as a presenting acuity of less than 6/12 in the better eye. The term blindness is used for complete or nearly complete vision loss.

Since the Global Positioning System (GPS) was introduced in the late 1980s there have been many attempts to integrate it into a navigation-assistance system for blind and visually impaired people.

Tactile alphabet Alphabet readable by touch

A tactile alphabet is a system for writing material that the blind can read by touch. While currently the Braille system is the most popular and some materials have been prepared in Moon type, historically, many other tactile alphabets have existed:

A touch user interface (TUI) is a computer-pointing technology based upon the sense of touch (haptics). Whereas a graphical user interface (GUI) relies upon the sense of sight, a TUI enables not only the sense of touch to innervate and activate computer-based functions, it also allows the user, particularly those with visual impairments, an added level of interaction based upon tactile or Braille input.

The term "ADA Signs" has come into common use in the architectural, construction and signage industries with the advent of the Americans With Disabilities Act, or ADA. The Americans with Disabilities Act regulates accessibility; and includes requirements for signage that is conveniently located and easy to read both visually and through tactile touch.

A talking tactile tablet or T3 is a graphic tablet with a touch surface that can be used as an input device that uses swell paper to create 3D overlays and connects audio files to parts of the overlays. The device is connected to a computer and run with a programme CD, and has a tactile surface which produces touchable icons that provide audio feedback when they are pressed. It can be used to help visually impaired users to interpret diagrams, charts and maps by producing a tactile, touchable image, and audio feedback.

A sighted child who is reading at a basic level should be able to understand common words and answer simple questions about the information presented. They should also have enough fluency to get through the material in a timely manner. Over the course of a child's education, these foundations are built on to teach higher levels of math, science, and comprehension skills. Children who are blind not only have the education disadvantage of not being able to see: they also miss out on the very fundamental parts of early and advanced education if not provided with the necessary tools.

Braille e-book Refreshable braille display using electroactive polymers or heated wax to raise dots

A braille e-book is a refreshable braille display using electroactive polymers or heated wax rather than mechanical pins to raise braille dots on a display. Though not inherently expensive, due to the small scale of production they have not been shown to be economical.

Alternative formats include audio, braille, electronic or large print versions of standard print such as educational material, textbooks, information leaflets, and even people's personal bills and letters. Alternative formats are created to help people who are blind or visual impaired to gain assess to their personal and leisure information either by sight, by ear (audio) or by touch (braille).

Cecogram Package containing items for visually impaired persons

A cecogram, also known as literature for the blind, is a letter or a parcel that contains documents or items intended for visually impaired persons. Cecograms can be sent or received by such persons, as well as by organisations that provide assistance to the visually impaired. Cecograms are either partially or entirely exempt from postage.

Joshua Miele American scientist and inventor

Joshua A. Miele is an American scientist and inventor who specializes in adaptive technology design. Since 2019, Miele has been a Principal Accessibility Researcher at Amazon Lab126, a subsidiary of Amazon that works on hardware products. Before assuming his current position, Miele conducted research on tactile graphics and auditory displays at the Smith-Kettlewell Eye Research Institute for fifteen years. Among his work at Smith-Kettlewell is Tactile Map Automated Production, a web application for generating tactile maps of streets printable with a braille embosser, and YouDescribe, a web platform for creating and listening to audio descriptions of YouTube videos. He received a MacArthur Fellowship in 2021.

References

  1. ↑ McCallum, Don. et al. 2005. The design and manufacture of tactile maps using an ink-jet process. Journal of Engineering Design. Vol. 16, no. 6. December. pp. 525–544.
  2. ↑ Ahmed, Kafeel., McCallum, Don., & Sheldon, Derek F. 2005. Multiphase Micro-Drop Interaction In Ink-jet Printing of 3D Structures for Tactile Maps. Modern Physics Letters B. Nos. 28&29 pp. 1699–1702.
  3. ↑ Jehoel, Sandra. et al. 2005. An Evaluation of Substrates for Tactile Maps and Diagrams: Scanning Speed and Users’ Preferences. Journal of Visual Impairment & Blindness. February. pp. 85–95.
  4. ↑ Griffin, A.L. 2002 Feeling it out : the use of haptic visualization for exploratory geographic visualization. Cartographic Perspectives, 39. pp. 12–29
  5. ↑ Jehoel, Sandra. et al. 2005. An Evaluation of Substrates for Tactile Maps and Diagrams: Scanning Speed and Users’ Preferences. Journal of Visual Impairment & Blindness. February. pp. 85–95.
  6. ↑ Siekierska, Eva., Muller, Anita. 2003. Tactile and Audio-tactile Maps within the Canadian Government On-Line Program. The Cartography Journal. Vol 40, 3. pp. 299–304.
  7. ↑ Golledge, Reginald G, Rice Matthew., & Jacobson Denial R. 2005. A Commentary on the use of Touch for Accessing On-Screen Spatial Representations: The Process of Experiencing Haptic Maps and Graphics. The Professional Geographer. 57, 3 pp. 339–349.
  8. ↑ "Home of KGS Corporation". KGS Corporation.
  9. ↑ "Hyperbraille". Hyperbraille.
  10. ↑ "Home of Tactisplay Corp". Tactisplay Corp.
  11. ↑ "Full Page Braille Display being Launched by Tactisplay Corp". Tactisplay Corp.
  12. ↑ Yayla, Lisa. 2009. Huseby Zoom Maps: A design Methodology for Tactile Graphics. Journal of Visual Impairment & Blindness. May. pp. 270–276.
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