Floor estimation for human computer interfaces

Human Computer Interfaces (HCI) may allow a user to interact with a computer via a variety of mechanisms, such as hand, head, and body gestures. Various of the disclosed embodiments allow information captured from a depth camera on an HCI system to be used to recognize such gestures. Particularly, the HCI system's depth sensor may capture depth frames of the user's movements over time. To discern gestures from these movements, the system may group portions of the user's anatomy represented by the depth data into classes. This grouping may require that the relevant depth data be extracted from the depth frame. Such extraction may itself require that appropriate clipping planes be determined. Various of the disclosed embodiments better establish floor planes from which such clipping planes may be derived.