A light emitting element and a light receiving element is placed in such a manner that the light axis of a light emitting element constructing a light emitting circuit and the light axis of a light receiving element constructing a light receiving circuit cross each other. For all pixels that become active within the time window a corresponding analog value of the pixel is sampled and held in response to a logic signal indicative of another pixel currently being active, and an incident time of the pixel going active is established. A portion of the conversation that is relevant to the shared digital image is automatically extracted and combined with the digital image to form the composite multimedia product. This invention also relates to the preparation of said compounds. An exemplary embodiment presents a movie to the viewer, detects an occurrence of one of a plurality of event capture triggers, captures at least one image of the viewer in response to detecting the event capture trigger, and stores the image of the viewer. mean and the standard deviations of different image portions relative to other portions.