3. The method of claim 2 wherein detecting the hand comprises refining an object that includes an arm portion and a hand portion to remove the arm portion.
3. The method of claim 2 wherein detecting the hand comprises refining an object that includes an arm portion and a hand portion to remove the arm portion. 4. The method of claim 3 , wherein refining an object that includes an arm portion and a hand portion to remove the arm portion comprises: identifying a hand region; determining that the identified hand region includes a portion of an arm and a portion of the hand; locating a thinnest portion of the hand region; classifying the thinnest portion of the hand region as a wrist; and removing points beyond the wrist such that the arm portion is removed.