REPRESENTING SPACE FOR PRACTICAL REASONING

The paper describes a new approach to representing space and time for practical reasoning, based on space-filling cells. The new models can represent a bounded region of space using only a finite number of cells, so they can be manipulated directly. They have useful notions of function continuity and region 'connectedness'. The topology of space is allowed to depend on the situation being represented, accounting for sharp changes in function values and lack of connectedness across object boundaries. Algorithms based on this model of space are neither purely region based nor purely boundary based, but a blend of the two. This new style of algorithm design is illustrated by a new program for finding edges in grey-scale images.