Recognition

Recognition, along with Detection and Identification, is one of three key tasks commonly associated with imaging systems. This term refers to the ability of an observer to distinguish between different classes of targets, such as identifying the difference between a human target and a vehicle.

These tasks are typically described using statistical terms, as they historically relate to a human observer’s capability to perform them. The effectiveness of each task is often expressed in terms of the percentage of average observers who can accomplish it under specific conditions. For example, “50% Probability of Recognition” (often written as P(recog)_50%) means that 50% of an average group of observers would be able to distinguish between targets of different classes within an image. According to the Johnson Criteria, it takes 6 pixels across the critical dimension of the target to achieve the 50% level of recognition. See Critical Dimension.