Method and apparatus to count people

A people counting method comprising:

• calculating, by executing an instruction with a processor, a degree of similarity between a first characteristic dataset representative of a first face detection in a first image at a first image location and a second characteristic dataset representative of a second face detection in a second image at the first image location, the first and second images included in a plurality of images representative of an environment during a first period of time of a media presentation;
• storing, by executing an instruction with the processor, the first characteristic dataset and the second characteristic dataset in a plurality of characteristic datasets associated with the first period of time in response to the degree of similarity not satisfying a threshold;
• storing, by executing an instruction with the processor, the first characteristic dataset in the plurality of characteristic datasets and discarding, by executing an instruction with the processor, the second characteristic dataset in response to the degree of similarity satisfying a threshold to limit a number of stored characteristic datasets associated with the first image location;
• and
• comparing, by executing an instruction with the processor, the plurality of characteristic datasets to each other to determine a number of unique faces in the environment during the first period of time.

A non-transitory computer readable medium comprising instruction that, when executed, cause a machine to least:

• calculate a degree of similarity between a first characteristic dataset representative of a first face detection in a first image at a first image location and a second characteristic dataset representative of a second face detection in a second image at the first image location, the first and second images included in a plurality of images representative of an environment during a first period of time of a media presentation;
• store the first characteristic dataset and the second characteristic dataset in a plurality of characteristic datasets associated with the first period of time when the degree of similarity does not satisfy a threshold;
• store the first characteristic dataset in the plurality of characteristic datasets and discard the second characteristic dataset when the degree of similarity satisfies the threshold to limit a number of stored characteristic datasets associated with the first image location;
• and
• compare the plurality of characteristic datasets to each other to determine a number of unique faces in the environment during the first period of time.