Since electronic and open environments became a reality, computational trust and reputation models have attracted increasing interest in the field of multiagent systems (MAS). Some of them are based on cognitive theories of reputation that require cognitive agents to display all their potential. One of them is Repage, a computational system based on a cognitive theory of reputation that focuses on the study of two important concepts: Image and Reputation. The possible integration of these Repage predicates into a cognitive agent architecture, like the well-known Belief, Desire, Intention (BDI) approach implies the definition of these two concepts as mental states, as a set of beliefs. In this paper, we specify a belief logic that captures the necessary elements to express Image and Reputation and we study their interplay by analyzing a classical definition of trust on information sources. Keywords. Image, Reputation, Probabilistic Dynamic Belief Logic, Multi-agent systems