1. An audience measurement device, comprising: memory to store a first frame of data and a second frame of data; and a first data analyzer to: trigger a two-dimensional recognition analysis, in connection with the first frame of data, on two-dimensional data points representative of an object detected in an environment, the trigger based on satisfying a first trigger event, the first trigger event being one of (1) a distance between the object and a sensor of the environment satisfying a threshold distance, or (2) elapsing of a time interval; and in response to determining that the object is recognized as a person in the first frame, trigger the two-dimensional recognition analysis in connection with the second frame, the second frame subsequent to the first frame, the two-dimensional recognition analysis of the second frame performed on two-dimensional data points representative of a location in the second frame corresponding to the location of the person in the first frame, the first data analyzer implemented via a logic circuit.