Detecting a composition of an audience

An apparatus to detect a composition of an audience of an information presenting device comprising:

• a camera to capture at least one image of the audience;
• a processor;
• a memory storing computer readable instructions which, when executed, cause the processor to:
• determine a number of people within the at least one image;
• and
• develop a prompt signal requesting the audience to identify its members if a change in the number of people is visually detected;
• and
• an output device responsive to the prompt signal to output an indication requesting the audience to identify its members, wherein the processor determines the number of people within the at least one image by:
• (a) determining at least one difference image between at least two images captured by the camera;
• (b) developing at least one shape from the at least one difference image;
• (c) identifying at least one center of the at least one shape;
• (d) adding a symbol having a predetermined size and indicative of the at least one center of the at least one shape to a histogram;
• (e) repeating (a)-(d);
• and (f) if any symbol in the histogram grows beyond a predetermined threshold, counting the symbol as a person.

A computer readable medium storing computer readable instructions which, when executed, cause at least one computer to:

• capture at least one image of an audience consuming a program;
• determine a number of people within the at least one image;
• and
• output a prompt signal requesting the audience to identify its members if a change in the number of people is detected from the at least one image, wherein the at least one computer determines the number of people within the at least one image by:
• (a) determining at least one difference image between at least two captured images;
• (b) developing at least one shape from the at least one difference image;
• (c) identifying at least one center of the at least one shape;
• (d) adding a symbol having a predetermined size and indicative of the at least one center of the at least one shape to a histogram;
• (e) repeating (a)-(d);
• and (f) if any symbol in the histogram grows beyond a predetermined threshold, counting the symbol as a person.