Tactile graphics are different from visual graphics, and never shall the
two be the same.
Visual graphics contain such visual information as color, intensity
(contrast,) and perspective. The last item enables the viewer to
intuitively recognize the angle of the view, and to some extent,
differentiate between objects in the forfront from those positioned further
back in the view.
We must have better tools in order to enrich the amount of information that
can be encoded in a tactile graphic. At a minimum, we need three
dimentional tactiles with smoothly variable X, Y, and Z axis. Mr. Jaquis
refers to these tactiles as bas reliefs. The term "bas relief" comes from
the world of art, and was used in ancient times to adorn vases and funeral
urns with raised images.
These tactiles do not have to be made to true scale of the objects they
represent. For instance, the Z axis can be fore-shortened, so long as the
original information is intuitively recognizable. The same is true for the
X and Y axes.
The APH and Howe Press maps are about as good as they can be made with the
tools available at the time they were produced. We should use these maps.
We should not accept them, however, as being good enough. We have to
continue to demand better tactiles. And, we in the R&D Committee should
spend more time investigating new materials and technologies with potential
for making better tactile graphics--especially those emerging
technologies based on computer controled production.
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