Object-Oriented Image Processing in Smalltalk: Using Complex Operator Objects

In this paper we present concepts for modelling image processing operators within an object-oriented system like the Smalltalk environment. The operators, which are described in a knowledge-base and receive their functionality from a large, proven, and well-established C library, are integrated into the Smalltalk environment in order to provide this environment with extensive image processing capabilities. Within the Smalltalk class hierarchy the operators are modelled as independent objects — as tools used for creating, manipulating, and evaluating images, regions, and features on a highly abstract level. Besides this functionality, the operator objects represent knowledge about the corresponding image processing procedures. This information attached to the operators is profitable not only for being questioned by the user, i.e., the software developer, but also for being evaluated by tools and applications based on operator objects. Moreover, this knowledge is used for the automatic generation of appropriate Smalltalk operator classes that build the interface to the underlying C library. In addition to the implemented representation of the operators, we will discuss the kind of representation, the scope, and the use of the operator knowledge.