A contact event is a record that maintains information about the interaction, such as the duration, the person performing the action, and a description of the action, if available. We look for evidence throughout the class hierarchy to differentiate between classes sharing the same parent. Example of a book object created from parent class Article . The person class works in tandem with the Extraction layer to locate people based on a model of a person. The former component is c haracterized by physical properties, such as hand size and skin color, as well as physiological considerations, like arm span.
Skin color is described by an array containing all of the flesh tones in the person's hands.
This color distribution is used in the Extraction layer to assist in the segmentation the hands. We elect to use the YUV color space instead of RGB because of its separation of the luminance and chrominance bands. It maintains a list of scene objects and person objects. We also construct a matrix to hold conditional probabilities between every two articles. This layer searches for correlations between object interactions in order to classify particular activities or to identify certain human behaviors.