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Extensions to the Two Dimensional Qualitative Representations

This chapter has presented two methods for qualitative representation of two dimensional shape: one has an emphasis on constructing two dimensional shape descriptions from hierachical combination (through subparts) of primitive shape features, using axes to describe size, position, and orientation. The other has an emphasis on segmenting the boundaries of two dimensional shape into elements that are qualitatively homogeneous, with position described in terms of proximity between elements, and a global size ordering.

Each of these has been used to construct scene descriptions in the LISP language, and has been used as input to one of the simple planning systems described in chapter 5. The last three sections of this chapter describes possible extensions to the implemented representations which were not required for the examples, but would add both power and generality for applying a qualitative shape representation to a wider range of problems.


Alan Blackwell