Initialising and Terminating Active Contours for Vague Field Crisping

Many aspects of spatial language concerned with realworld features and the relationships between them are essentially vague. While this vagueness is managed quite effectively in natural language communication between people, there are currently only very limited facilities for interpreting such language when used to communicate with computers. To overcome this shortcoming a fieldbased model has been developed to provide a continuous representation of the spatial aspect of this vagueness. Using fields to represent spatial information is not a new idea. Couclelis (1992) described how people alternate between a field and object views of the world, something a GIS also needs to be able to do. Yamada et al. (1992) describe a fieldbased system for locating the area described by a spatial expression. Liu et al. (2008) present a general field model and Guo et al. (2008), use fields to model the uncertainty and error in expressions such as “10km N of Kuala Lumpur”.