Tactile graphic
Encyclopedia
Tactile graphics 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.
Tactile graphics can be seen as a subset of accessible image
s. 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.
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 embosser
can also be used to produce tactile paper maps.
Ink-jet tactile maps are made by layering a specially designed ink. Each layer is cured by a UV irradiation before the next layer is added. This technology is an offshoot of other industries such as circuit board manufacturing and biomedical applications
The substrate for tactile maps is a very important attribute since different materials can enhance or reduce legibility and durability. Several different types of substrates can be used to produce a tactile map. These included, 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.
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.
Typical tactile elevations Thermoformed maps usually have an elevation of at least 1mm. Swell Paper averages 0.5 mm and brail 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.
Audio tactile maps or graphic tablet 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.
Force Feedback tactile maps 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.
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.
Visual impairment
Visual impairment is vision loss to such a degree as to qualify as an additional support need through a significant limitation of visual capability resulting from either disease, trauma, or congenital or degenerative conditions that cannot be corrected by conventional means, such as refractive...
person can feel them. They are used to convey non-textual information such as maps, paintings, graphs and diagrams.
Tactile graphics can be seen as a subset of accessible image
Accessible image
An accessible image is an image that is made accessible to the visually impaired through touch, sight,smell and sound.-External links:*****...
s. Images can be made accessible to the visually impaired in various ways, such as verbal description, sound, or haptic
Haptic
Haptic technology, or haptics, is a tactile feedback technology that takes advantage of a user's sense of touch by applying forces, vibrations, or motions to the user...
(tactual) feedback.
One of the most common uses for tactile graphics is the production of tactile maps.
Tactile Maps
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 printer.Thermoform is one of the most common methods of producing tactile maps. This process is also known as vacuum forming
Vacuum forming
Vacuum forming, commonly known as vacuuforming, is a simplified version of thermoforming, whereby a sheet of plastic is heated to a forming temperature, stretched onto or into a single-surface mold , and held against the mold by applying vacuum between the mold surface and the sheet.The vacuum...
. 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 embosser
Braille embosser
A Braille embosser is a printer, necessarily an impact printer, that renders text as tactile Braille cells. Using Braille translation software, a document can be embossed with relative ease, making Braille production much more efficient and cost-effective....
can also be used to produce tactile paper maps.
Ink-jet tactile maps are made by layering a specially designed ink. Each layer is cured by a UV irradiation before the next layer is added. This technology is an offshoot of other industries such as circuit board manufacturing and biomedical applications
The substrate for tactile maps is a very important attribute since different materials can enhance or reduce legibility and durability. Several different types of substrates can be used to produce a tactile map. These included, rough and smooth plastic, rough and smooth paper, microcapsule paper, Braillon and aluminum. Many factors should be considered when choosing a substrate
Substrate (printing)
Substrate is a term used in converting process such as printing and Lamination or coating as a more general term to describe the base material onto which e.g. images will be printed and to be laminated as per the packing specification required for the product...
these include but are not limited to function, durability and portability.
Tactile Map variables Just as Jacques Bertin
Jacques Bertin
Jacques Bertin was a French cartographer and theorist, known from his book Semiologie Graphique , edited in 1967...
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.
Typical tactile elevations Thermoformed maps usually have an elevation of at least 1mm. Swell Paper averages 0.5 mm and brail 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.
Audio tactile maps or graphic tablet 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.
Force Feedback tactile maps 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.
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
Raster
Raster may refer to:* Raster graphics, graphical techniques using arrays of pixel values* Raster graphics editor, a computer program* Raster scan, the pattern of image readout, transmission, storage, and reconstruction in television and computer images...
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.
External links
- Haptic learning demonstration videos — touch audio learning
- Alternate Text Production Center
- Tactile graphic resource page
Tactile Map external pictures
- http://www.google.com/images?q=tactile+maps&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&source=univ&ei=bO0ATfyKEcu4ngeTuNjlDQ&sa=X&oi=image_result_group&ct=title&resnum=2&ved=0CCwQsAQwAQ&biw=986&bih=816 Google tactile maps
- http://www.lib.ucdavis.edu/ul/about/exhibits/img/disability-4.jpg U.S Capitol tactile map
- http://myloc.gov/_assets/Exhibitions/braille/ExhibitionItems/Assets/lb0016_enlarge.jpg Capitol Hill and The Mall tactile map
- http://www.derm.qld.gov.au/property/mapping/images/tactile.jpg Tactile map of Australia
Tactile Map external web sites
- http://www.clickandgomaps.com/ ClickAndGo Wayfinding Maps
- http://www.tactilevisioninc.com/maps.php Tactile vision maps
- http://geogratis.cgdi.gc.ca/geogratis/en/option/select.do;jsessionid=51337932695C312A0ADC11F399113864?id=BD6FA9EA-3570-52D4-32D8-56BA3E4C04CB Tactile maps of Canada
- http://www.nctd.org.uk/ UK National Center for Tactile Diagrams
- http://dots.physics.orst.edu/tactile/tactile.html Oregon State University Resource Guide
- http://www.perkins.org/resources/scout/education/geography/tactile-maps.html Perkins Scout tactile maps