An interactive raster graphics system and language for artists and designers
This thesis is concerned with the design of a computer graphics system
for in particular artists, and in general surface designers (where
surface design refers to the design of 2Dimensional surfaces, e.g.
wallpaper, carpets and fabrics). It is argued that the artist tends
to be tentative both in terms of plans of action and also the meaning
of the image. This is reflected in changes of mind that have
consequences on the artists plans and on the structure of the perceived
image (i.e. an image perceived in one way may be seen differently later
On both counts, it is argued, conventional vector based computer graphics
does not possess the desired flexibility. Raster graphics employing a
'bitmap' to represent the picture for display offers new potential and
greater flexibility. In particular it permits a view of interactive
graphics, described as "communicating interpretations" in which the user
is seen as being involved in communicating features in a visual scene
shared by the man and the machine to the machine. In so doing the user
is able to operate on objects in the picture as and when they are perceived.
A language (GLIMPS) is described which not only permits the user to
generate pictures but also includes facilities for extracting and
operating on perceptual features of a picture. GLIMPS makes it possible
for both "physical" (region) and "non-physical" (figure on ground)
properties of the 'bitmap' to be handled.
In conclusion it is argued that the "communicating interpretations" view
is more generally applicable in interactive computer graphics.