UNCERTAINTY MANAGEMENT FOR RULE-BASED SYSTEMS WITH APPLICATIONS TO IMAGE-ANALYSIS

In image analysis, there have been few effective procedures that deal with a wide class of imagery acquired by different sensors under different environmental conditions. The success of a given classification algorithm is dependent upon pattern familiarity, background, and the image acquisition process. Thus, with the inaccuracies in the acquisition process, as well as incomplete or incorrect knowledge about the pattern classes, one cannot place complete confidence in the classifier outcome. There has been increasing success in making decisions under such uncertain conditions by using a rule-based approach with effective uncertainty management, which involves identifying the causes of uncertainty and developing mathematical models for the same. These are incorporated into the rule structure so that the result would be a set of choices or decisions, with a set of associated certainty values or confidences. This paper proposes a ''unified'' methodology to combine the uncertainties associated with evidence for a given proposition, which is then systematically propagated down the decision tree. The relative importance of propositions as well as the rules themselves have also been considered. Finally, the methodology has been applied to an ATR problem and the results, when compared to some existing methods, show the overall effectiveness of this approach.