Interpretation Of Aerial Imagery Using A Constraint-Based Approach

This paper describes a constraint-based image understanding system (COBIUS) for aerial imagery interpretation. COBIUS consists of knowledge bases for domain objects, spatial and temporal constraints, control strategies, blackboard areas to instantiate hypotheses of objects and constraints, and an image feature database to fuse results from multiple image segmentation modules. Unlike previous efforts on knowledge-based image understanding where domain-specific rules are encoded for image interpretation, in COBIUS, domain-specific knowledge is represented in terms of generic temporal and spatial constraints. A set of generic constraint manipulation and hypothesis formation rules are used to perform formation, evaluation, propagation, and satisfaction of constraints and hypotheses. More importantly, constraints are represented hierarchically and are no different from the representation of domain objects. This representation avoids time-consuming graph matching processes for image interpretation and provides greater representation modularity.