1. A system for directed area search in visual imagery, comprising: a domain knowledge database configured to store Bayesian network models comprising visual features and observables associated with various sets of entities, where the observables are associated with feature/attention models for locating the observables in visual imagery; a top-down module configured to: receive a search goal comprising a set of entities to be located in an image; generate a plan of action for locating the set of entities by combining the Bayesian network models relating to the set of entities to be located according to joint probability distributions to yield a combined Bayesian network model, the combined Bayesian network model describing visual features associated with the set of entities, where the Bayesian network models and associated visual features are obtained from the domain knowledge database; and partition the plan into a set of tasks, each task comprising at least one observable to be located in the visual imagery; and a bottom-up module configured to: select a relevant feature/attention model for each observable from the domain knowledge database; search the visual imagery for the at least one observable using the selected feature/attention model; and output search results as a set of candidate entities.