The name "Utiles" has multiple sources:

  • utile, adjective: advantageous, useful

  • útiles (Spanish: implements, tools)

  • a contraction of "useful tiles"

The Utiles project, in any case, is an R&D effort in tactile graphics:

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. 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.

Using assistive technologies such as VoiceOver and refreshable braille displays, a blind person can access textual content from assorted online documents (e.g., articles, blogs, books). However, the associated images (e.g., charts, diagrams, maps, pictures) are not accessible, in general.

Fortunately, some interesting possibilities could be at hand (:-). If the image can be transformed into a tactile surface, the sense of touch can detect differences in height, texture, etc. With practice, a blind person can use her fingertips to detect, interpret, and absorb the encoded information.

The tactile surface should be located on an object that is easy to produce, carry, handle, and store. A laser cutter can fabricate such an object, cutting it to any desired shape and engraving the "top" surface with image data, braille patterns, etc.

I'm currently using thin, 8.5" x 11" sheets of acrylic glass (PMMA) and planning to add a printed backing sheet of heavy (cover stock) paper. These materials are reasonably inexpensive, light, durable, and well-behaved.

Alternatively, other digital modeling and fabrication techniques (e.g., 3D printer, CNC Mill, water jet cutter) could be used to emboss or engrave patterns into other materials. The resulting surface can either be used directly or as a master for vacuum forming of thin plastic sheets.


In the general case, simplifying and transforming image data involves some Really Hard Problems. Photographic images, for example, pose difficult challenges. However, line art (e.g., charts, diagrams, maps) seems tractable, particularly if some human assistance (e.g., interactive editing) is allowed.

Although Utiles can be easy to carry around, the fabrication equipment is not. Also, the fabrication process is far from instantaneous. In short, we're not talking about casual access to image data: defining and fabricating a Utile takes significant time and effort.

That said, it should be possible to create a "rendering pipeline" that can create Utiles with turnaround times of a day or two. This is certainly good enough for experimentation and usability testing; we can look at improving performance once we have a proof of concept...


Human fingers are very sensitive to variations in height, texture, etc. For example, it is quite possible to detect a difference in height of 0.001", simply by running a fingertip over the location. Given good feedback, fingers can also manipulate objects with great precision (e.g., moving a microscope slide to view various parts of a bacterium).

The braille system, developed in 1824 by Louis Braille, takes advantage of this tactile sensitivity to encode text:

Braille is a tactile writing system used by people who are blind and low vision. It is traditionally written with embossed paper. Braille users can read computer screens and other electronic support thanks to refreshable braille displays. They can write braille with the original slate and stylus or type it on a braille writer, such as a portable braille note-taker, or on a computer that prints with a braille embosser.

However, braille uses only a small fraction of the available sensitivity. Tactile image renditions typically use much higher resolution, etc.

Breakout Pages

  • NoBat - biomimetic, ultrasonic navigation aid
    (formerly known as Utile Eyes)

This wiki page is maintained by Rich Morin, an independent consultant specializing in software design, development, and documentation. Please feel free to email comments, inquiries, suggestions, etc!

Topic revision: r121 - 24 May 2016, RichMorin
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