Declarative graphics

Abstract

A standard approach to describe pictures is the use of formal grammars. This, and the strong link between definite clause grammars and logic programming, motivates the design of the declarative picture specification language presented here. The language is relational and rule based. A specification is akin to a definite clause grammar and may be executed bottom-up for picture recognition or top-down for generation. Picture execution provides features of constraint based graphic programming. A picture specification may be viewed as a data structure allowing programs to reason about a picture's structure and to manipulate it for dynamic and interactive applications.